A few recaps of John Carmack's talk at QuakeCon are online, where id's upcoming Doom game was touched on a few times. You can check out summaries on 3DActionPlanet, Shugashack, and Stomped. A couple of points of interest:

• The game will be more focused on single-player than multiplayer play.
• An XBox port will be a "no-brainer" due to the similarity between the Xbox and a PC, but PS2 and Dreamcast ports are more in doubt.
• The game will ship with all the traditional map authoring and mod development tools, and that the game will be more like the original Quake in ease of modification than subsequent games.
• The use of bots is yet to be determined.
• There will be a test version released, like Qtest, etc.