At the Hasbro Italy 2009 Brand Preview, some more details on who will be appearing in Transformers: Revenge Of The Fallen have been confirmed. SPOILERS AHEAD!
Jetfire and Devastator are both confirmed for the sequel, with Jetfire definately being an Autobot. Jetfire has also been seen, in toy form, combining with Optimus Prime, like he did in Transformers Armada, to form some super robot. If this happens in the film is yet to be seen.