Michael Kaplan is a previous collaborator of J.J. Abrams, and worked on both Star Trek and Star Trek Into Darkness, as well as Mission: Impossible Ghost Protocol. Kaplan himself confirmed his involvement with Star Wars: Episode VII, telling Clothes on Film the following statement.
"I am very excited to be working on Star Wars. I'm so looking forward to collaborating, once again, with J.J."
John Williams had http://movieweb.com/john-williams-wants-to-make-music-for-star-wars-episode-vii/previously hinted that he was involved with the music for Star Wars: Episode VII, despite Michael Giacchino having scored all of J.J. Abrams' past directorial efforts. Williams has now confirmed with FMM Film Music Media that he will be in charge of the music for this new sequel, having previously conducted the soundtracks for all 6 movies in the franchise.
"I fully plan to and expect I'll be there. It will be good!"
How do you feel about this mix of J.J. Abrams' new crew of collaborators coming together with some of the old guards of the Lucasfilm empire?