As much as WoW will always have a special place in my heart, I don't think I could ever get back into it seriously again. As much as I like the idea of levelling, and as much as I like certain classes and mechanics, I cannot face the end game grind again. Everything I do in that game is overshadowed by the fact that I'll have to grind heroics, then Naxx, then Ulduar then whatever else they've added since I last played.
No thanks, have better things to do with my free time than be shouted at by, or shout at, other players.