Assuming full Meditation, Improved Spirit Tap multiplies Spirit-based regeneration by 2.75 while active, but Shadow Priests aren't Arcane Mages, so the term "enough regeneration" likely exists.

Then extra spell power from increased Spirit through Twisted Faith, which is extra 15% of non-tapped Spirit in spell power. How much Spirit are we talking about?

And critical strike damage bonus increase by 50%, when less than 50% of damage is capable of critical effect to begin with (it's around 30-40% I believe).

Now as Affliction Warlock you can have Improved Shadow Bolt. It, even if no longer affects DOTs (in a super-nerfed state) should beat DPS-wise DPS components of both increased critical damage and Improved Spirit Tap proc.

But that's not all. Eradication, as any haste increases amount of Shadow Bolts you use compared to amount of DOTs. Shadow Bolt can crit, so more of Affliction damage can crit. Everlasting Affliction gives some more time to Shadow Bolt too, that can crit. New Fel Armor reduces amount of Life Tap/Dark Pact you need so you cast more of your filler which is (you guessed it!) Shadow Bolt that can crit. On the other hand free refreshing of SW:Pain and Haste for Shadow Priests increases amount of damage done by Mind Flay, that cannot crit. If you compare who has more damage capable of critical effect, Affliction Warlocks win this over Shadow Priests.

True, although it worries me that they're placing even more emphasis on Shadowbolt in the Affliction tree. They'd to better to make Shadowbolt crits increase DoT your damage by a large percentage or something else rather than simply ramping up Affliction's Shadowbolt DPS.

Is seems Blizzard is STILL of the opinion that DoTs do too much damage, are still too OP. We gained, what, 20% more to bonus damage in deep affliction, but the ISB nerf cancels out that to a large extent. It'll be a PvP buff, but neutral in a PvE setting. On top of it, people really need to look at the mana cost and dps gains on the last trainable version of corruption. Blizzard is very much an Indian Giver when it comes to DoT buffs and it's not fooling me one bit.

Affliction is being steered into the SB spam (shadow) spec. Do not expect the 51 ptr to be PVE viable because they WANT you to grab ruin. Destruction is being steered into a fire spec. Neither playstyles are engaging to me...and I'll probably be changing my mains for WotLK. I'm not complaining, I've played the lock for a long time, it's probably time to move on.

Third--don't assume Fel Armor is going to actually allow us to Life tap less. As it as been pointed out earlier, our mana costs for our latest spells have increased substantially. It does appear it is intended to cancel out the extra mana regen from fel armor as it stands now. It's way too early to say fel armor is a pve buff. All of this is conjecture however, as nobody is level 80 and running raids to actually see how everything interrelates.

This is my belief as well. To an extent, its a case of, why bother with all the messy ramifications of buffing DoT's, when they already have crit scaling with SB. Can't really blame them frankly, i'd much rather err on the side of caution when balancing DoT's, and keep PvP in mind than increase their power and ruin is the easy way out. As it stands currently, affliction locks with ruin scale comparably to fire mages with crit rating. The debate currently really isn't because affliction locks don't scale well with crit (they do, and will in wotlk if specced for it), the problem is people don't think its 'afflictionish'.

Some numbers on Demonic Pact:

Assuming your pet has windfury, does not have any +hit, does not have any expertise, and leaving out Demonic Empowerment, i simulated the following uptimes:

at least 1 stack: 90% uptime
at least 2 stacks: 80% uptime
at least 3 stacks: 72% uptime
avg stack = 2.4

The talent seems to be worth between 2% and 2.5% sustained dps for your group. This is fairly expensive for 5 points relative to other similar talents. Both Ret Paladins and BM hunters spend 3 points for a similar or superior effect.

A similar effect that is a bit easier for each class to keep up. I would have expected Blizzard to allow for 100% uptime, what with the health boost. Then again, maybe Blizzard will do a 180 and allow for hit/crit/haste scaling.

As to everything that Blizzard has been doing with Affliction, it'd be interesting if they had some ideas for a single spec with Afflcition, with some freedom for the rest of the points. Maybe several mechanics to make Drain Life more viable for DPS, better coefficients for DoTs, and so on. While I can understand they want to play it safe, they're leaving gaps open, and wasting time designing stuff that people may not even use.

Edit: Edited for clarity towards Demonic Pact.

And just to complicate things, if there's a single Frost Mage present, he'll have another +2% about 35% of the time.

There is also 3% hit from the elemental shaman totem because totems are raid wide buffs now.

And because melee hit and spell hit are the same now of course(Edit: though that might be an item only feature.. so it might not be relevant), though if elemental shaman don't get some form of additional raid utility they will still be just average.

Melee Hit and Spell Hit are not the same. The Ratings have been consolidated, but not the stats.

If you run the numbers for felguard with melee totems and buffs you gonna see that 0/50/21 is far superior.

This occurred to me this weekend: What about the Spirit reduction on Demonic Embrace? If Spirit becomes a prominent stat for Warlocks and with that deep Destruction talent to increase spell damage based on Spirit, you're probably going to want to avoid Demonic Embrace, pigeon-holing all Destruction Warlocks into 2/2 Imp healthstone and 3/3 Imp Imp. But if you want everyone to have 3 healthstones then 2 Warlocks are going to have to take a 1% and 2% spirit hit.

There's a fair number of fights where you need a minimum health value. Given the choice between keeping that 5% spirit, vs. losing it but being able to stack 15% less stamina to meet those minimums (and thus wearing more damage gear instead), which comes out ahead? (I'm not sure, but that's what you need to balance.)

It actually makes the Demonic Embrace tradeoff something worth thinking about, which is a nice switch. That said, anyone full Demo will want 5/5 for the stam as it scales into the pet. I still think as a rule people will end up taking DE, no one wants to be as squishy as a mage and I doubt the boost to spirit is going to be that substantial. Maybe we won't have to avoid it like the plague any more, but I doubt spirit will ever be something we seek out. Besides, even now "technically" the best dps spec wouldn't include DE as the spirit does give damage through IDS.

Just for the sake of gauging the value of that 5% spirit, I'll use my own stats (based on the assumption that warlocks and mages will have much more similar stats at 80):

30% MP5 while casting now: 162.8
30% MP5 while casting with -5% spirit: 154.6

The more I read about wotlk talents the more I get the feeling that Blizzard has no clear idea on where to put warlocks talents and skills.

When I think of destruction, I think of juggling with fire and shadow like no tomorrow. Devastating whatever comes across my way. Immolating myself and jumping a group of unbelieving travellers.(Oh wait, they gave mages that skill)
Destruction means sacrificing one, or both, of your eyes and kidneys for dark magic that makes peaceblooms explode on gather. That's destruction.

So, in my very humble opinion, the destruction tree should be filled with stuff that goes boom - bigtime.
Like

Burnt skin
Burns the targets skin, inflicting fire damage every second and reducing healing effects taken over 15 seconds
Every fire spell hitting the target will increase the damage done by 1%.

Improved Conflagration
Your Immolates and Burn Skins have a x% chance to trigger conflagration when expiring.

Shell of Pain
Reflects all melee attacks for a short duration, causing 50% of the damage done to the attacker.

Dark bombardment
Drops void zones in close range, exploding and dealing damage when stepped on.

How many other talents are there with meaningful negative effects? Apparently Demonic Embrace becomes one. Though I would like to add that Nether Protection is so far incompatible with every fight designed to be tanked by Warlock.

Demonic Embrace could drop 5% of Stamina bonus, and then have Spirit effect either removed or reversed. It wouldn't even be a problem if it just had Spirit effect reversed without Stamina bonus reduction, because Stamina and Spirit are stats oriented on rather opposite activities.

As for people having same or different Healthstones, maybe Improved Healthstone should be dumped for good, Healthstone should become Unique (3), and all kinds of Healthstones would receive 20% buff that they previously received through talents. As a replacement they could either pull increased healing taken from old Fel Armor and new Demon Armor, or move there Demonic Aegis, cutting it to 2 points since it's not really worth 3. Or something around pet survival in PVE.

I actually don't mind the varying levels of Healthstones. It's a nice benny from having multiple locks in a raid. It's not THE reason to take more than one, like WF/Heroism is currently for shammies, or Blessings are for pallies...but it is nice, and it does force your raiding warlocks to communicate with each other. Is that really such a bad thing?

I've never liked the -spirit portion of Demonic Embrace though...so far as I know (I may be wrong here, so correct me if I am), it's the only talent in the game where actually taking a talent lessens your actual stats. There's MANY talents, obviously, that by taking, you lock yourself out of some other, better talent, of course. But I don't believe there's anything that does this...and while it doesn't mean anything currently, to have it in play when spirit FINALLY means something to locks in 3.0 is going to be a tough sell.

The current form of DE is also counter-intuitive at the stage of player skill when one can first acquire it. I remember when I was leveling up my warlock when I first started playing, almost two years ago now. Instant Corruption I immediately, even as a new player, recognized as an OMG, have to have skill. After that, of course, one likes to have more health, but I didn't realize then that spirit wasn't important to a lock, and I stayed away from it for a VERY long time. Had I known then what I know now, of course, I would have taken it, and in all likelihood, would have survived many more of those fights that I died in while leveling. Bottom line, I understand why the skill is there, but at the same time, I think it needs a major overhaul.

Oh, and not *quite* every fight...Leo can be successfully tanked with Nether Prot, because the damge incoming is AoE based, and therefore Nether prot doesn't kick in with it.

Playing With Fire (mage fire talent) increases damage recieved. Not a stat reduction, but nonetheless a negative effect. Their new Burnout talent is looking to possibly be a noticeable negative, but that's still in development. Also, Improved Garrote back in the day used to increase number of ticks but lower damage per tick creating more damage overall but lowering damage when the DoT would not run to completion, but that's since been removed.
EDIT: Thank you Manly for reminding me of the Mage Tax: while not listed on the character panel, Improved Fireball/Frostbolt used to lower the coefficient, creating less damage per spell.

I don't like improved healthstone because the primary benefit (20% bigger HS) is basically useless, and the only reason to actually take the talent is to cheese your way out of the "unique" tag, something I would almost consider borderline-exploitative. This also creates situations where not taking the talent is flatly superior to taking the talent, or where 1/2 is superior to filling or not taking the talent, both of which I disagree with on principle.

There's some ace-mod I bumped into that's designed for Warlock tanking with NP. I forget the name but its supposed to automatically click off Nether Protection when it comes up.

In arenas it's not borderline, it's patently exploitative. The only reason it is less obvious in raids is because the effects of having 2-3 healthstones vs 1 healthstone is so marginal it rarely makes a difference on any given encounter.

I wouldn't say that. 2-3 Healthstones per raid member can help a hell of a lot in every fight in Sunwell. You could often be the victim of multiple Burns, Encapsulates, Flame Sears etc evenly spaced out enough that your first healthstone comes off cooldown.

As for arena, I don't think there are many arena teams housing 2 Warlocks, but if you are its probably a 5v5 team and the games often don't last long enough for it to come off cooldown anyway.