Robert Orci has posted a possible hint towards when the first teaser trailer for Transformers: Revenge of the Fallen may appear. On Don Murphy’s message board, he answered the following question:

Q: So Bob, any idea if we’ll see a TF2 trailer during the premiere of Fringe in September???
A: Maybe — or maybe in front of EAGLE EYE… who knows

Eagle Eye is a thriller starring Shia LaBeouf and produced by Steven Spielberg, Alex Kurtzman and Roberto Orci, so links between the films make it more likely for a teaser to appear beforehand.

Of course, it is just as likely a Michael Bay style bluff.