Looks like the second Transformers movie is already being filmed, which is expected if they want to have it released in 15 months time (last one took about a year in post production/animation).

The article in the link below should pretty much confirm one particular character in the second movie. I think there might be a few Transformers fans now trying to scope out that location to see what other vehicles are being used in the second movie.
Go to this link for more