There is one thing I really hope is going to come in to play during Cataclysm, Survival being important.
At the moment DPS and Healing is very one dimensional. You spec and gear to do the most damage or healing possible, any talents or gear you pick otherwise are a waste. As such the game becomes very cookie cutter.
Generally I would like to see a bit more importance to Utility brought back, by that I mean anything that isn’t directly related to doing damage, healing or tanking. As Blizzard has said before talents like Body and Soul are what they are aiming for, useful stuff that adds a lot of flavour and utility but doesn’t directly add to your DPS or Healing etc.
Some of my favourite fights are ones that involve the class style really shining through rather than just being about blowing stuff up. Gluth is a good example if this, actually being able to use abilities and skill you don’t often get to use is extremely satisfying.
Bring the player not the class is the problem here, although I agree in theory that it is a good idea it does mean a lot of classes have had their utility stripped out, or at least the need to use it. Bring it back, like shake and vac.