This Slashdot post from John Carmack (thanks shul and Frans) offers his reflections on the release of DOOM 3, as he proudly says: "I think it is the best game we have ever made, and it exceeded all of my expectations." A subsequent reply from the id Software lead programmer on the subject of the OpenSource release of Quake III Arena, states: "By the end of the year. There are still a lot of higher priority things, but it is coming soon. Hopefully punkbuster will keep the source release from having any negative impact on the player community." Here's a bit more from the first post on id's near-future roadmap:

Amidst all the various Doom ports and expansions, we are starting up on our next game. It will have a new rendering engine, which will be keeping me busy for a while, but the only other thing we are saying for now is that it won't be a sequel to any of our previous work. We have a really solid team that did a lot of maturing through Doom's development, so I have high hopes that it won't be another four year odyssey.