RE5 is not an Xbox 360 exclusive. Speaking of the Halo 3 trailer, nothing impressed me like that in a long, long time. I expected it to look better than multiplayer footage, but this totally blew me away. It's right up there with Too Human on my hype-o-meter.
Speaking of which...
Too Human -
http://gamersyde.com/news_4580_en.html
Killzone 2 also looks great, although not as impressive as the target render from two years ago, but that was to be expected.
Killzone 2 -
http://gametrailers.com/game/1668.html