Just read an article on a presentation at the latest KMWorld in San Jose in November 05 about the link between a game (world of warwind, i think).
This article discusses how a MMORG (massive multiplayer online roleplaying game) could be usable in a business environment. It discusses the behaviours people show in those games and how they apply/are similar to real world behaviour.
I think that a MMORG that reflects a business environment would be interesting. It could serve the purpose of virtual meetings (documents/presentations could be shown online, in vitual meeting rooms, people represented by avatars, the document actually visible), for getting to know people (virtual watercooler, virtual dating, etc.), or even virtual training sessions.
I think the problems with this environment for business is that people perceive it as play without consequences. If a MMORG would be applied to real world problems, there would be real consequences.