They're doing 2 more sequels, the cast have signed on but the the writers havent decided yet.
On May 30, 2007, Dreamworks greenlit two sequels to Transformers,[76] and Shia LaBeouf,[77] Megan Fox[78] and Peter Cullen[37] signed on to return. Michael Bay has not signed, saying "I'm trying to keep some leverage for the negotiations."[37] Writers Roberto Orci and Alex Kurtzman are undecided but may not return because "we want to have a reason to do it, not just say, “it’s a business, it’s a franchise, we’re going to go do the second one because that’s what we do and we’re going to get the big money,†and Star Trek by the way is taking up kind of all of our time."[31]
Soundwave is intended to be a new major character in the sequels,[9] with his presence allowing a proper introduction of mass-shifting.[7] Producer Tom DeSanto has "a very cool idea on how to introduce the Dinobots and Constructicons."[79] If he decides to helm a sequel, Bay may put in an aircraft carrier character, an idea which was previously too expensive for the first film.[80]