Authors note on the Compendium itself
Finding, compiling, formatting and reposting all this information is a LOT of work.
I'm personally thankful for any comments, useful additions and stupid questions - keeping track of it all is very time consuming.
The purpose of this compendium is not to discuss raiding specs, best in slot gear or raid encounters - it is to give Warlocks a good look at Cataclysms changes to their class, suggested levelling and gearing routes and other eventually missed information.
For quite a few readers a lot of this compendiums content will be familiar, but to the majority this will be quite interesting and informative.

As unfinished as this may seem at any point, it all starts with one or two stones and once I have parts out of my head, I can write on others.

Instances
In order to queue into instances with the Dungeon Finder, you need to have 2 requirements fulfilled:
a) Discovered the dungeon entrance
b) Adequate average item level
You can always jump into the dungeon manually, avoiding b).
Following the list of required ilvl per dungeon(Patch 13117) as well as the ilvl of items that drop in them

Instance name	ilvl required	ilvl drops
Blackrock Caverns	xxx	279
Throne of the Tides	xxx	279
The Stonecore	272	316
Vortex Pinnacle	272	316
Grim Batol	305	333
Halls of Origination	305	333
Lost City of the Tol'Vir	305	333
Heroic Instances	329	346

Dungeon entrances
Cataclysm Beta - 5-man Roundup and Navigation Guide
Special notice: By all means get a sea horse before trying to swim down to The Throne of the Tides.

Factions
One of the more interesting questions is, which factions does one come across and which should one prioritize to do heroics with first with a tabard of choice. Revered items are all 346 rare, exalted items are all 359 epic.

Dragonmaw Clan / Wildhammer Clan
The Dragonmaw Clan is native to Twilight Highlands(so doable at 84+). You will get reputation throughout the zone with them and will get friendly after the first small quest series.
Their Quartermaster is, contrary to popular believe, not located in Dragonmaw port, but in Bloodgulch(center of map).
The Alliance equivalent of him is residing in Thundermar.
Potential interests:
[Bone Fever Gloves]
[Band of Lamentation]
[Yellow Smoke Pendant]

The Guardians of Hyjal
The keepers of Hyjal are your friends throughout the zone, takes no more than a handful quests to get friendly with them.Their Quartermaster is located inside the very first building at Nordrassil.
Potential interests:
[Arcanum of Hyjal]

The Earthen Ring
The Earthen Ring, introduced way back as keepers of nature, are now native to Vashj'ir, Deepholme and Twilight Highlands. Their Quartermaster resides at the Silver Tide Hollow in Vashj'ir.
Potential interests:
[Mercury-Coated Hood]
[Helm of Temperance]
[Cloak of Ancient Wisdom]
[Flamebloom Gloves]

Therazane
Therazane can only be found in Deepholme. At the end of the Deepholme questlines you are left with <to be checked> honored of Therazane, while being hated with them before that. Additional rep can also be gained with daily quests.
Their Quartermaster resides at Therazanes Throne.
Potential interests:
[Lesser Inscription of Charged Lodestone]
[Greater Inscription of Charged Lodestone]
[Diamant's Ring of Temperance]

Ramkahen
Ramkahen is the faction you'll get in touch with during Uldum. After the inital quests(granted you take 1000 rep over 200gold) you will almost be friendly with them.
Their Quartermaster resides in Ramkahen itself.
Potential interests:
[Robes of Orsis]
[Desert Walker Sandals]

Tol Barad Factions
[Insidious Staff]
[Stump of Time]

Profession crafts
Several early raiding items can be crafted again.
Full list of WoWhead
[Breeches of Mended Nightmares] / [Flame-Ascended Pantaloons]
[Dreamless Belt]
[Dungeoneering Guide]
[Elementium Spellblade]
[Darkmoon Card: Volcano]

Quest rewards worth noting
[Overly Intelligent Robes]
[Sandals of the Courier]
[True Archaeologist's Bracers]
[Very Manly Staff]

Gems
sp00n opened a highly interesting topic in the Public Discussion regarding gems and changes.
You might want to check out his detailed gem conversion overview.

Blizz stated lately(granted I ever find that particular blue post of GC again I'll link it) that socket bonuses will be better in Cata.

Archaeology
Archaeology has only a few nice BoA items you can get, and besides chances of getting them being totally random, do not underestimate the time needed to level it. As long as it is unconfirmed whether there is a Archaeology level requirement on actually getting these rares I will go with the assumption that it's just random.
Staff of Sorcerer-Thane Thaurissan
Ring of the Boy Emperor
undecided
Tyrande's Favorite Doll

The staff and the trinket are fairly "easy" with being dwarf and night elf, you get those commonly and can farm them without much "overhead" in other fragments.
The ring however is Tol'vir. As of right now on Wowheads data there are 6 rare Tol'vir items and it is a huge pain to gather those fragments.

If you are a collector going for all and have spare time, which is unlikely in the early cata days, have a shot at it.
But if you are planning on trying your luck - rather keep your hands off Archaeology till you have a decent amount of gear and time off.

Video Box
Please bear in mind that videos reflect the knowledge at a given time and information given might have changed from that point already.
Optecs detailed Cataclysm Warlock changes guide - Date 6th October 2010 - Patch 13117
Part 1
Part 2
Contains pretty much everything that has been changed up to this point.

And the more detailed guide Optec did for TotalHalibut:
Destruction
Demonology
Affliction
Random things and questions

#note Points to write about:
Items crafted by professions

Something to add about glyphs. The interface is changing such that you get a list of every glyph you've ever learned available to you at all times, after you use a glyph the first time. A little pre-planning and snagging them now before everyone rushes at once to complete their collection might be a good idea. Plus, there's an achievement!

Good start.

Will you be including anything about warlock gameplay in this? Rotations/specs/etc?

Also, information about the soul shard system change might be helpful.

Is currently not the case @ beta build 13117, not that it matters all that much but felt like saying it.

I would appreciate some feedback on levelling times, specially people that quest/have quested and of those who only ran dungeons.
Also, if anyone could throw me a screenshot of the Alliance equivalent of the Dragonmaw Clan - I'd appreciate it.

Totalbiscuit will be doing the warlock guide rather soonish, gonna add that then.
Interface point is cut short for stated reasons - If anyone wants to do a write-up after all, feel free to do it.

When I lvled through pure questing, 83, 84, 85 all took aorund 3h each, I think 84-85 was the fastest taking a little less then 3h. 80-82 has been change since I did them so I wouldn't speak of it. I'd expect quest-leveling times to be around the double on live, due to limited access to completing the quests. I'll PM you a pic of dragonmaw alliance soon!

You said dungeons won't give much faction rep - Does this means that the reputation-tabards won't give us rep until we're in heroics?

You no longer need to discover the dungeon entrance. It was supposed to go live in 4.0.1, but they decided against it, though Wailing Caverns is currently bugged on live realms and will not let you queue unless you've discovered it.

There are a few questions that come up on a regular base, some towards end-game raiding and some towards details.
I´ll add them to the initial post soonish but I´d appreciate useful feedback, logs, approved simcrafts and explained maths before I throw them up there.
Please also note that for the sake of keeping this thread clean I would also appreciate if anyone wants to add questions or add hot posts if interest you can simply PM me those, but as usual no one will keep your from posting anyway.

Questions:
Does Aftermath on RoF have an ICD?
Does Aftermath on RoF have a DR(diminishing return)?
Does Aftermaths RoF stun share a DR with other stuns?
Does Aftermaths RoF have a DR limit(aka proc 3 times, then have an ICD)?
Does Shadowburn have a use in a warlocks DPS rotation?
Does Searing Pain have any use in a warlocks DPS rotation?
Does at any point SoC outperform RoF as AoE?
When using BoH(Bane of Havoc) with a steady secondary target, should we also dot this target with Immolate/Corruption?
Would it be beneficial to "twist" the imp back and forth in a situation where BoH and a steady secondary target is used? (main and focus target for simplification)
What spec(+glyphs) should a warlock use for "tanking"? How does this spec compare to other classes?(ups and downs)
Does SP(Searing Pain) compete with a normal DPS rotation threat and damage wise?
In which cases should I use Doomguard and in which would an Infernal be better?
Does the Infernal summoning stun share DR?
Is it beneficial to SB a boss-add-trash-mob(granted experience gain applies) to replenish my shard count for DPS?
If no class in my group/raid provides the 5% spellcrit debuff, should a Destro warlock shoot a SB every 30 seconds?

As additional note, I´ll soonish merge Warlocos first off infos into this and freshen up the styling a bit(if my fat fingers manage).

#edit felguard -> doomguard obviously :/

My first suggestions (most of them have to be proven soon):

My experience with shadowburn on the beta shows thats it could be worth to use it in a standard rotation with a very high priority, right after conflagrate. Its crits lied somewhat around 35-40k last couple of raids, whilst my incinerates only crit for about 28-31k. There may be a point where at high haste and especially mastery rating most of the actual common destruction casts will surpase it, but I'm not sure about it.

Do you mean stacking burning embers up on max on your primary and your bane of havoc target as well by speaking of "imp twist"? If so, I guess its haste-related a lot but may squeeze out some extra dps. Didn't tested it yet.

I don't know if it was already mentioned in Warlocomotifs Thread already, but I stood under the impression that the infernal is quite inferior to the doomguard when it comes to single target and the other way round in a multitarget fight. In case the doomguard does what it should do. Of course if you want to rank - the doomguard does not show up in the logs, the infernal does instead.

If shadowburn is worth a GCD even above a filler (see above) and you manage to switch targets without damage loss it should be used to replenish Soulshards whenever possible.

Yes, 5% crit should way outweigh a single missing incinerate in my opinion. If the Numbers SimC 4.0 pointed out are reliable, Crit should have a very high performance in the first tier of raiding anyway.

Hello,

my experience in the beta and I'll try to make tests as soon as I'll be able to login again.
Does Shadowburn have a use in a warlocks DPS rotation? Yes it should be usable, in raid tests I had crit for an average 23k and 10k not crit.

When using BoH(Bane of Havoc) with a steady secondary target, should we also dot this target with Immolate/Corruption? Never tried it, I'll take a look but it'll force to manage other timers and on raid bosses I tried, I spent my time moving and trying to not take aoe damage.

In which cases should I use Felguard and in which would an Infernal be better? I use doomguard on single target boss and infernal on multi-target ...meaning almost never.

If no class in my group/raid provides the 5% spellcrit debuff, should a Destro warlock shoot a SB every 30 seconds? Definitively yes.

Does Searing Pain have any use in a warlocks DPS rotation? No math to prove it, but the mana cost is important (12%).

Hope it helps.

"In which cases should I use Felguard and in which would an Infernal be better?"
Wait, what? Felguard is a pet, infernal is a guardian, that isn't a choice - You can have both up.

Assuming you meant the doomguard though, the sims recently showed infernal to be better on single target, so we ought to be using that. However, blizzard have stated that this isn't the design, so I would probably expect them to bring doomguard damage up or infernal down; the design is doomguard single target, infernal AoE.
Another thing to take into consideration is that sometimes, a doomguard will be more practical on account of it being ranged.

As for dotting secondary targets and imp twisting, in an ideal situation, these would net you more dps - You're getting to use a spell higher up in the priority list more often, or doubling the damage from imp's embers.
However, the other target might not be debuffed to take extra damage, and this might reduce that spells DPSC in comparison to what spells on the main target have, and reduce the position in the priority list when it's cast on a non-main target. Probably still a DPS increase to cast, though.

There are two things you should think about before you do this though.
The first is, how much does the dps on that target matter? If two things both need to be DPS'd down, then great - If the second target doesn't need to go down immediately, and the primary target is something that is more likely to be an issue if it is kept up, you might find that the dps on the second target isn't worth as much as the dps on the 1st; sure, it's worth the same on the meters, but in practice, might not be worth doing.
The second thing is, how practical is it? Are you going to lose dps time on boss by trying to switch imp back and forth? How many keybinding slots do you have left to make macros to swap the imp about?

Not a direct answer, but my thoughts on those questions

It seems to be enough to have an adequate avg Ilvl including any items in your inventory.
So in case you dont want to break a set/loose some special item while leveling just keep random blues in your bags and ilvl should be no problem.

To add to this, the blues have to be equippable(aka no Plate Items, but str/agi neckpieces/rings/cloaks are fine). This leaves clothies at the biggest disadvantage in terms of getting the requirement to get into the heroics, but its better than nothing.

For reaching the heroic ilevel threshhold, don't forget about pvp gear. I had some extra honor left over from WOTLK, which I used to buy a new pvp trinket. You don't even have to wear it to raise your ilevel. The pvp gear is particularly useful for this because the blues are a high base ilevel.