Merrick here...
The official website of the TRANSFORMERS: REVENGE OF THE FALLEN game features two robots not previously revealed.

IMAGE REMOVED PER REQUEST OF THE PEOPLE DESIGNING SAID SITE (I GUESS THAT'S WHO ASKED US TO TAKE 'EM DOWN...)

These originate HERE. THIS post at Transformers Movie Chronicles identifies the characters in questions as: "The Twins", saying they're "the robot modes of the Chevy Beat and Chevy Trax"