Well, the DOOM Movie Full Trailer is available from Fileshack. I'm not sure if I'm convinced, it's not going to be more than a B movie in my opinion, and the first person shooter scenes looked pretty odd to me (in a movie that is). As one commenter in the Shacknews threads comments:
[...] of course, the first person mode which actually looks pretty cool, though I think I'd prefer a few 30 second to 2 minute sequences of it than a single 12 minute section of the movie that I think they're going to do.Guess we'll see Oct 21!