Rumor has it that the reason Williams is going to start writing music in the next couple of weeks is because Disney wants to attach an Episode VII teaser to "Into The Woods" which opens on Christmas Day. The teaser would feature original music written by Williams. Nothing has been confirmed, but, if true, this may explain why Williams is starting early... So this may be another instance like "Hook" or the first "Harry Potter" where Williams wrote music specifically for the teaser and trailers.