I'm fairly sure there's little chance of that. Blizzard has stated int he past they had no intention of creating "resistance fights" which would require either gearing up with resistance or bosses who had resistance. Forcing mages to go frost or shaman to go resto isn't in line with their current model.

I seriously doubt that they'd give us a set bonus that was gimped for the content associated with the set. My sense is they've also largely abandoned the notion of bosses with resistances/immunities to particularly schools of magic and/or debuffs - while it makes sense thematically, screwing over *all* fire mages and nerfing enh shaman clearly has some issues from a design perspective. So my guess would be that all resistances will be more or less standard.

My immediate impression of the set is that, like the set bonuses, it favors Combat over Assassination - high haste, very little mastery. The high amount of crit is also not really ideal. From a Mutilate perspective the early leader for weakest piece (depending on what offset pieces are available) would appear to be the chest - neither crit nor expertise is notably good. For Combat I'd say the early leader is the legs, for similar reasons.

Also interesting is the socket bonus on the shoulders - usually a 2-gem socket bonus gives 20 of a stat, not 10. I would assume its just a bug, but it wouldn't be the first time we had an item with an unusual socket bonus.

Actually, that's just a typo by me - the shoulders have 1 red socket. I'll update the post.

Regarding resistances - a blue post recently confirmed that no encounters in Firelands will require fire resist gear, and no bosses will have fire immunities (sorry, can't find the source atm).

From MMO-Champion:

Link: MMO-Champion - Cory Stockton interview on Buffed.de - Patch 4.2 Extra Information

Just posted to MMO-Champion today. Most likely this change is just to keep it in line with where the proc is now and later into Firelands and later tiers it will fall away as just an entry level raiding trinket.

Looking through the new 4.2 items I stumbled over a new scope.

Flintlocke's Woodchucker - Item - World of Warcraft

Considering that 300agi is quite a number and we usually dont have a different use for a scope (ranged crit or attack power anyone?) I could see making use of the proc from shooting and then engaging just for the sake of the chance of procc'ing?

Since it is a proc for ranged weapons I'm not sure it was meant with rogues in mind at all. Probably more to give hunters a high end proc "enchant" in line with landslide, windwalk and power torrent. That said, we may have use of it during phases where only ranged can reach the boss, but I see the dps loss of using it at any other time being not worth it.

New round of datamined items. We can now make a complete set with pieces for every slot, pre-Heroic that is (only missing a 278 main hand for combat); note that the reputation ring is of heroic ilvl. Given the number of bosses I very much doubt we'll see many more different pieces.

Item	slot	ilvl	Agi	Stam	Crit	Hit	Exp	Mastery	Haste	Sockets	Socket bonus	dps/speed
Flamesign Necklace	neck	378	227	341	156	144
Flamebinder Bracers	wrists	378	227	341	148		154
Flamebinding Girdle	waist	378	282	454		167			211	1blue	10agi
Firestone Seal	finger	378	227	341	140			158
Viridian Signet of the Avengers	finger	391	236	384				134	181	1red	10agi
Morningstar Shard	thrown	378	128	192		88	81					744.1 / 2.0

EDIT:
This should clear the previous doubts we had on the set bonus:
The Fire damage-over-time effects from some set bonuses work like Ignite, and will accumulate and refresh damage just as it does.
The rogue 4-piece bonus never picks hit or expertise, and never picks the same rating twice in a row.
source

As per the edit in above, we got a slight tier info update.

Tier 12 Set Bonuses - Feedback - Forums - World of Warcraft

The ones related (or hopefuly related) to us are below.

•The rogue 4-piece bonus never picks hit or expertise, and never picks the same rating twice in a row.

•The Fire damage-over-time effects from some set bonuses work like Ignite, and will accumulate and refresh damage just as it does.

With the news that the proc never picks the same in a row, I would assume its slighly more profitable for tricks+trinket stacking (50% chance instead of 33%). it at least lets us know what we won't get based on what we just had.

This should increase the EP value of crit for all specs significantly I would think. Getting crit up to the point where it would be hard to go 4secs without a melee crit (Poisons won't count for it).

It's like Ignite, stacking and rolling? Keeping that stack up the entire fight would be huge compared to letting it drop a few times.