I remember that E306 announcement trailer, looked awesome. When I saw it I realised what Bungie meant by Halo 3 would not ape GoW's ridiculous detail but still look good in it's own right.
http://www.gametrailers.com/player/10454.html
Too bad the final game watered down the graphics a lot, with a resolution decrease, depth of field effects removed and no AA. Halo 3's 'clean' art style really needs AA to make it work, and it looks fantastic in that announcement trailer.
Master Chief's armor in the trailer is also much better looking that the one in the final game. Since this was all running in real time (Bungie even detached the camera and moved it around the scene in a vidoc), I wonder why the final IQ was so much lower in the final game, which had another year of development time behind it.