Amazon.com has posted a preview of the official comic book adaptation of Transformers: Dark of the Moon scheduled for release on May 25th. If you click the cover or "Search inside this book" you get about the first seven and last seven pages of the trade. A system error revealed more pages than intended leading to major story points being revealed.I don't consider characters and alt modes to be spoilers. So knowing that, I will reveal that the leaked images did confirm that Soundwave's alt mode is the silver Mercedes-Benz SLS AMG as indicated by the game image. Also Wheeljack is a confirmed Autobot in the movie but I saw only has his name being said. Did not see his robot mode or vehicle mode to confirm if "Einstein", the blue 2011 Mercedes-Benz E550.
It should be noted that adaptations usually work from a final movie script along with designs and storyboards offered by production. However, as Sir Peter Jackson points out, there are three phases to a script - writing it, filming it and editing it. As a result what the comic shows for a scene and what the movie shows may not be the same. Certain elements like the major plot points, characters, etc tend to stay static due to cost but the specific details can easily change (scenes, characters, etc being left on cutting room floor).
If you wish to seek out the spoilers, that is up to you. Be warned the pages did reveal major plot and character developments in the story. If you are even a little bit sensitive about spoilers it is advised to not seek out that information.