There's a DOOM III Q&A on Gaming Invasion talking with Tim Willits, the lead designer on id Software's upcoming DOOM III (unless I miss my guess, this was conducted waaay back at QuakeCon). They discuss his inspirations in pursuing a career in game design, working with John Carmack, how DOOM III is coming along, challenges the game has presented, the most impressive feature of their new engine, multiplayer support, mod support, supporting lower-end hardware, weapons, per-poly collision detection, and more.