Michael Bay recently spoke with Forbes magazine and confirmed that shooting on a fourth "Transformers" is slated to begin in May in order to have the film ready in time for a June 27th 2014 release. He adds that the film isn't so much a reboot as a refresh:
"To freshen the franchise, we redesigned everything. The history of the first three movies is still there. We start four years later and there's a reason why we're meeting a new cast.
We keep the 'Transformers' the way they were. It's just four years later. There's a reason the Transformers are redesigned. We're trying to broaden the franchise and give it more places to go."