After much speculation, I think we can finally state that the Twins will NOT be in Transformers: Dark of the Moon. This is what Michael Bay had to say on Shoot for the Edit:
After the internet posting of a nice review by someone who saw Transformers Dark of the Moon, the writer had not been clear on one thing. He misstated that the Twins are in the film. They are not.
So I am offering a $25,000 REWARD to anyone who can find them performing in Transformers 3, on July 1, when the movie opens.
Update: From Capone:
Hey, everyone. Just to be 100 percent clear, I'm not referring about the "The Twins" here; they are most definitely not in this film. I'm talking about Wheelie (Tom Kenny, who also voiced Skids in REVENGE OF THE FALLEN) and other similar smaller robots, who act like streetwise teenagers.