Sounds to me like this is really Orci's show; The two junior writers are just there to get experience and gain street cred by working on a major title. Whatever input they have's gonna be minimal, and Orci won't let them get too far into canon-breaking waters.
The director announcement is the one to watch. Barring another writer's strike, the script's just gonna be clay for the director (and cast) to mold and even reshape on set or in the editing room. If no other worthy name pops up, I wonder if Orci himself might try to take a stab at it.