There was a decently sized write up in the most recent OXM that I read yesterday on UT3. It's going to be better than Gears of War graphically and is going to be gunning at Halo 3 for a better FPS gameplay wise.
The frontpage team wrote up a quick article based on the OXM write up with some scans:
There's going to be plenty of vehicles and the pace of the game should be very fast based from what I read. It's going to be interesting to see if Halo 3 will have any competition in the FPS realm on the 360. I don't think there has been any mention of a release date for the 360 or PC. (or PS3)
Edit - Scans where you can read the article from the Epic Forums: