News has come out that the actor Shia LaBeouf from the Transformers Movie Franchise is quitting the franchise, together with Director Michael Bay, after the third movie.
He mentioned the possibility of a reboot.

This was discussed on MTV. Meanwhile in the latest sequel to 2009’s Transformers Revenge of the Fallen, the Autobots are back. Lead by Optimus Prime, the Autobots face the Decepticons once more, during a dangerous US-Russia space race. Once more Sam Witwicky has to help his robot friends.

LaBeouf said “I’m not coming back to do another one”, giving rise to the possiblity of either a new actor replacing him or a full reboot for the fourth movie (which Paramount is interested in).