Game Girl Advance has an article by Richard A. Bartle on why it is too soon to add real-time voice communication to massive multi-player online games. I'm not incredibly interested in MMOGs or real-time voice, but the article contains a pretty accurate taxonomy of game designers, some good points on immersion, suspension of disbelief, adding features for marketing purposes and how that affects your effective audience, and a nice summary of what MMOGs are all about: not being yourself. (If you like the bits on immersion, make sure you've read Scott McCloud's "Understanding Comics" for a practical theory on the downside of realism.)