To get this out of the way first, no new Doom III footage was shown and Carmack said the game was "pretty close" to release.More info here
Carmack confirmed that id is already thinking about their next first person shooter project after Doom III is due. Unlike Doom III, which is in its fourth year of development, Carmack said their next game is only supposed to take a couple of years to make, mainly due to the fact that they don't plan to make a huge graphical leap as they did from Quake 3 Arena to Doom III.
Carmack revealed that he and id thought about, and then dropped, a plan to revisit Quake II, remaking the same exact game but use an all new graphics engine as a way to show off the engine without having to concentrate on game development.
Doom III almost finished

John Carmack told Homelanfed that Doom III is pretty close to release..