Time for some rambling. I'm just looking at classes and specs for the most part. There will be ample time to do the quests over and over and over and over....
Prot Paladin: Sort of wonky. No more holy power seems to removed the rhythm of the rotation. The spec isn't super fun as is on live either. The appeal for me is going to be the utility you provide to the rest of your group and that is pretty much the same as it is on live as far as I can tell. You provide a bit more passive healing and damage to the group which is cool I guess. The other tank I played was Blood DK and it has zero of that so unless that changes people will very likely want Prot paladins.
Blood DK: Straight away I miss the little minigame you play where using runes gave you stacks of that talent that you could spend for runic power. You have one type of rune and one type of plague. Deathstrike is your runic power dump. Boneshield is maintained though a 2 rune ability. Bloodboil is just a 2 stack CD and costs no resource. Gorefield's grasp is baseline. It's fun. You don't really have a lot of the big emergency shit you do on live. What I really love about this spec on live is the self healing and resource management and that shit is not only still there, but may actually be more fun.
Arms Warrior: Gotta play a dps spec right? It's still the spin whirlwind spec that it is on live. The animation is new and is really really satisfying. It may be the tuning but the spec feels more self sustained then it does on live. It also feels faster. Stance dancing is sorta back as a toggle. For me the spec is really fun because of Battlecry (60 second CD, no rage cost, gives 100% crit chance for 5 seconds). Alongside a talent that gives you 2 charges of Mortal Strike... Also Cleave is back, but like... it's a 8 rage whirlwind (which is 20) but does half the damage. I suspect this for a talent called Fervor of Battle that gives you 2 rage for each target hit by cleave or whirlwind.
I gotta try Prot Warrior, All of the monk specs, Ret Paladin, and then it's up in the air I guess. Right now if Prot Warrior is good then warrior is probably going to be my choice as none of the DK dps specs really appeal to me.