Problem with WoW is every class is just like the others. No more "unique flavor". I can understand giving a "mini Mortal Strike" to another class, but giving it to half the classes? Same about Battle Rez, Replenishment, Paladins Aura buffs, and many others.
I actually thought it was fun in BC, where I could raid as feral - and be the best offtank in the entire guild, or with my undergeared Warlock that could make geared casters look silly.
It just became boring, although they did fix major issues (10 days trial, poor performance in a few situations, flight in Azeroth, outdated quests...)
And btw, I dont think WoW's expensive. I know it can be expensive for a kid, but anyone who works can pay day easily, and I dont know about you guys, but I find it very easy to spend more than $15 on a single night out (food, few drinks, parking fee, and so on).