Well, I cancelled my EQ account months ago, but I'm still on an Everlasting Quest for amusement and information. And last night I stumbled upon a fascinating website:
Lum the Mad
You may recognize the name "Lum the Mad" from Advanced Dungeons and Dragons.  But for whatever reason, TSR seems to be letting this guy get away with using their intellectual property as the name of a huge website with articles about all the "massively multiplayer" games out there.
It's fascinating reading, and there's plenty of great meaty stuff related to game design (often even in the articles that don't, at first glance, appear to have anything to do with it). In fact, I should have posted this in World Design, but I'm too lasy to cut-and-paste what I've written so far.
Granted, I've been aware of this site for less than 24 hours, so I may simply be in the throes of new-discovery enthusiasm. Still, I think there's a lot of valuable stuff to pick through here.
 The original AD&D Dungeon Master's Guide was probably one of the most re-readable, idea-packed books I've ever read. Almost as much so as The Dream Maker! :)