If you have a penchant for technical mumbo jumbo and didnt make it to QuakeCon you're in luck. Here is the video of John Carmack's keynote discussing DOOM3 technology and just a bit of what he's thinking will be next. They will be focusing on singleplayer again for the next project. MatthewPhillips has already done a good job of picking out some of his favorite parts of the talk in case you just want some highlights.