I would just like to point out that the man, the myth, the legend, will be doing the Sound FX and Sndtrk.
There's been quite a bit of speculation about the sound design for DOOM III, in particular if a certain musician of Nine Inch Nails fame will be involved. While an agreement has yet to be worked out for the full game, it can be told that Trent Reznor did all of the sound effects for id's E3 presentation. As mentioned, DOOM III will support Dolby 5.1 surround sound, and if you're able, seeing - and hearing - the presentation at full volume is an experience unto itself. As Reznor was quoted, "we want to get inside your head and make it an unpleasant place to be." (Gamespy.com)