Well, the alpha talent trees are out. I had a day to digest the information on mages and warlocks, and here are my ratings of various trees from the raider's perspective.

Mage fire tree: amazing. An already strong raid tree got two amazing talents: 30% more damage during the 'tough phases' of bosses, and an area effect disorient + damage on a 20 second cooldown. Unless the expansion will feature a lot of fire-resistant content this is clearly the best raiding tree. I am a little afraid dragon's breath will receive a nerf, because enough fire mages can keep an AoE pull permanently disoriented.

Mage frost tree: lackluster. Empowered frostbolt is improvement along the lines of other trees. The big question is the functionality of the elemental. My personal feeling, from having played a warlock for a long time, is to not place too much faith in pets that do not scale with equipment. My guess is the pet will be a farming/pvp toy, nothing more. The frost tree lacks a punch expected from mages, and the soft controls it brings to the table haven't proven to be useful in existing content. Frost still remains a great group pvp tree, however.

Mage arcane tree: either a raid requirement or a pvp tree. The crux of the matter is whether slow works on bosses. If it does, the arcane mage becomes the new eq shaman of wow -- melee boss content will be balanced around slow being applied full time, and an arcane mage will be necessary. If it doesn't, I don't see a reason to go deep arcane in raids -- it looks like a damaging but inefficient tree.

Warlock affliction tree: overrated. Affliction was due for a facelift for a long time, and many warlocks are excited by it. But what does affliction actually give you in raids? We get an extra dot as a 41 pointer, which helps with multipull dps. We get some raid utility with shadow embrace and malediction. And we have a lot of talents that add multipliers to dots. The problem is, warlock dots are at most a half of the warlock dps, even if empowered by a full affliction tree.

Warlock destruction tree: great up to 21, so so afterwards. The biggest change to destruction warlocks was the addition of a viable fire-based attack chain for single targets. This places warlocks at an advantage over mages, who have a dedicated tree for each element. In practice though, Conflag is a lackluster finisher over just doing another incinerate. Shadow and Flame has the same problem as the affliction tree -- it only improves half of warlock dps. The 41 pointer is a pvp talent killed by a long cooldown -- dragon's breath is much better.

Warlock demonology tree: the boring but optimal tree. Demonology is a weird tree. It tends to be full of two kinds of talents -- patently useless (spellstone, pet talents) and game-changingly overpowered (soul link, demonic sac). Generally, the later talents in demonology were so good people were willing to sink points into filler early talents to get at them. The expansion continues with this. What makes demonology good is not only the flexibility afforded by demonic sacrifice, and survivability afforded by soul link, but the fact that the damage multipliers from demonology work for ALL damage warlock does -- dot and nuke. A 40 point demonology spec gets +18% to all damage sources. Affliction and destruction may do a bit better in their own area, but the overall effect on dps is greatest in demonology. The felguard is an unknown as is the water elemental. We do know that Blizzard seems to be intending the felguard to be doing dps along with rogues. How well he will do this remains to be seen. Personally I think pets need to scale with gear in some way to remain viable in the long term.

Currently, I would spec 40 demonology/21 destruction. Compared to full affliction I give up 1 dot, and some dot damage (although 18% to dot damage isn't bad at all) while gaining a significant boost to shadowbolt spam, compared to full destruction I give up a fire based finisher and an aoe stun.

This doesn't need a new thread sorry, put it in the BC talents thread