The answer: "change a lot of things."
Recently, Bay spoke to Huffington Post about the decision to carry on the series (forever?) sans LaBeouf (who has not been particularly discreet about his unhappiness with the third installment). He cites a trip to the movie's theme park ride at Universal Studios as a kind of action director's version of enlightenment and confesses his fear that "someone could come in and screw it up."
So I'm thinking that if I do this last one, we set it on a new footing, we change a lot of things--but we keep the history of the three in place. But we broaden it so it can be set up and be carried on--it would have a better chance for survival, I guess.
Sidestepping the too-good-to-be-true irony that Bay is worried about someone else screwing up the series, it's pretty clear he's not quite ready to butcher his cash cow just yet/ever and that Transformers 4 will be much like the previous movies, but also different. Crystal clear. [Perez Hilton]