I play WoW as well.. And I have since pre-release, even.

Mainly a Hordie, I've got ten characters on my main server, and seven on my second. Three 80s, now, all decked in purples.
And I play.. Well; about four to an absolute maximum of ten per week...
So yes; WoW is a game you can play pretty successfully for just a few hours, and then leave it be. Of course; I'm not into heavy PvP or raiding, and I don't care all that much for achieving anything.. I just want to have fun, and chat with friends.

WoW happens to be that game for me.
I do always make sure I carry my weight in groups, though. (I prefer the guardian and healer roles.)