An announcement has been made as to the writer of the Transformers 5 movie (Akiva Goldsman), plus a claim that Michael Bay is going to be directing it.
(soon after that announcement was made Bay has said that he hasn't committed to it yet.... but didn't say that he definitely wasn't doing it either.)

Yes... three times now Michael bay has claimed to not be coming back, and it seems that he just can't cut the cord and walk away from his baby.

Also announced was an animated movie that looks like it could be an origin story based on Cybertron.