Here's your rumor of the day... The upcoming announcement of "new id games" at QuakeCon has everyone fruiting out over what the heck it could be. The guys at CVG have posted word (Thanks Mike) from "reliable sources" that Quake4 is and has been in development for 6 months at another development house. Of course in the same report they say that Quake4 was ditched in favor of DOOM (which is wrong) so the grain of salt grows a little bit.
http://www.computerandvideogames.com/story.cfm?sid=3008