What I'm hoping for future raid instances (25 mans) is that blizzard moves away from the conception that pretty much forces guilds to have 15x healers for nearly all encoutners (talking about 40 mans currently) and that offspecs are just not wanted. I'm hoping that blizzard will implement instances with wildly varying needs that it will make min/max'ing (people sitting outside the instance waiting to step in) so annoying that the offspecs get their chance and people can open their eyes.
I "think" this may be the way they are going after releasing 2.0 and looking at everyone's talent trees. There are so many synergies in the trees of so many classes like:
Priest: Shadow weaving, Misery, Vampyric Touch Vampyric Embrace
Druids: LoTP, Moonkin Aura, Tree form aura
Shaman: Spell crit totem, melee crit AP party buff, mana tide
Hunters: BM-Ferocious Inspiration(increase dmg of party by 3% for 10 sec when pet crit)
ect.
and other classes that would benefit so much from these party effects like the
40/21 arc/frost mage build (
http://www.wowhead.com/?talent-bc=Ri...xIziZZVA0coc0o) which would benefit a ton from the moonkin aura and totem of wrath (i think thats its name, spell crit totem) getting 150% bonus damage to frost crits. Along with all the physical DPS party buffs and magical damage increases.
With the shadow priest (I love what blizzard did with them, even though I'll be healbot for life heh), blizzard did such a good job that it simply will make so much sense to bring them to a 25 man raid. They directly increase warlock(and priest shadow damage) damage by 20% and other magical damage by 5%, so say you have 3 mages and 2 warlocks in the raid then 55% of their direct damage (this is neglecting damage they can do from increased mana from VT) is basically the priest's damage. As long as the shadow priest could do 45% the damage of a normal DPS class then he is the better choice if available (as well as the priest would obviously be able to do more than 45% he'd be even more valuable than the normal dps class).
I'm sure I've probably gone off on a tangent, but I really truely hope blizzard mixes up the lvl70 endgame instances tremendously and gives us some entirely brand new orignal content.