People are always talking about WoW as the 800-pound gorilla of the current gaming world (or at least the MMO sub-world). I don't have much non-WoW MMO experience, so I don't know where WoW innovated or where it just took/refined standard genre tropes. I do know that WoW must be making a big splash in the economic side of the gaming industry, with its massive legions of subscribers. I remember reading a while back about some game developers saying WoW was bad for the business because a lot of people were just playing WoW and not buying other games, and there may be something to that; I, for one, would almost certainly have bought a Wii by now if it wasn't for WoW.
What have you observed WoW's influence to be, good or bad, artistic or economic, in the gaming industry? What further influences do you predict it will have?