I'm an addict, play it with my roommates. Thing is, WoW's progressive element goes to pieces at the end of leveling, where all the "campaign" action is. Unlike standard RPG progression, where the group members (be it single player or MMO) are clumped up and you're limited to your window of progression, WoW's endgame pretty much zips you straight into your guild's window, regardless of guild. It's like using your friend's save on Final Fantasy or something. The result is everything revolves around what guild you're in, it's terribly imbalanced.