I'm certain my opinion will just be a drop in an ocean and will be either ignored or attacked.
Warlocks. I started to like the class this expansion and it feels like nerf, nerf, nerf. Their talent seems incapable of foresight.
Monks. Seemed like a cool deal. They seem mediocre at best. A few things I could rock the world with.. but we aren't anything special. Their talent seems incapable of figuring out the balance.
Warrior. I was gearing up as a tank FC. Then the nerf. Frustrating. A heads up or a refund would have been nice.
Multi-spec. I don't see a problem with it. I'm not interested in staying BM/MW on my monk and having to redo my action bars every time I want to play WW to jack around. No thanks.
I started in Wrath about 6 months before ICC came out. I'm what the vanilla players refer to as a "Wrath baby" -- and I assure you, it's not associated as a lovingly tone. Perhaps this game simply isn't for me anymore -- so I unsubscribed.
I've been playing more SC2. It seems their talented developers are capable of handling a strong balance. I'm not a great player in SC2 and I have no plans on investing the same amount of time that I put in to WoW -- after my experience of the WoW developers talent's failures... I just have no interest in it anymore.