Plug In Music via TFormers reports that Julien-K was tapped by Activision Blizzard to compose and score music for the up coming Transformers: Revenge of the Fallen video games coming out this summer. No details beyond that where provided about the game or the score itself. The band also had a single on the Transformers soundtrack released in 2007.
As for who is doing the score for the movie, it was officially announced back in July that Bay's favorite scorer Steve Jablonsky, who did the first film's score, is returning.*
* Thanks to Snortpocket for pointing out that Jablonsky's return was already official