Pally are OP when they have their bubble not on cool down otherwise it is just a Stun and then Rep, if you can deal with that you should win 9/10 times.
Prot Warrior I have seen on 49 are extremely strong for being Prot, 4.5k-5k hp and hit like a semi should never happen, while both MS and Fury builds are horrible from what I have played against
Going to be honest most classes seem pretty OP depending on Spec, I slaughter all forms of Shamans, but locks i can kill without much effort, but half the time i get Dotted and end up dying 10 secs after so is that OP that blizzard still allows locks dots to stay active even when they are dead? When not let my pet with BW on stay active then it is pretty much the same when there is 3-4 dot ticking on you