It is good to hear Peter Cullen doing Optimus Prime. The graphics are solid but not sure if what was shown is in game graphics are not. Now most significantly is the end of the trailer where they explicitly merge the Decepticon logo into the face on movie poster indicating a clear link.
In addition below are a few pictures from IGN that show off the character models and also Bumblebee fighting off a Decepticon. One thing I noticed about the Decepticon is that its alt mode may look very close to the M270 Launch Rocket System which I think was one of the photos in -=boM=-'s gallery. A gallery that Paramount has since had pulled from the web (update below).
Thanks to Danny for the heads-up on the trailer and to Adam for the pictures.
Update: Thanks to anonymous fans, below are the two pictures of the rocket launcher taken by boM at White Sands. While I think a rocket launcher is likely the alt mode of the first Decepticon fighting Bumblebee, the pictures are not conclusive proof that the rocket launcher is anything more then a prop for the film rather then being used as a Decepticon. Makes you wonder though.