I think JJ will need more time and he won't be on time to release in 2015, and it won't come out until 2016. Both Star Trek 1 and Star Trek 2 were delayed. I think the team working on the spinoffs will move much quicker. But yea, I'm sure all involved want Episode 7 first, then spinoffs, then Episode 8. Remains to be seen if it works out that way.
I just finished the film.. yes, the music is wonderfull.. Looking at these old films with such music, you really feel "you're watching a movie"! You feel you have a cinematic experience! Something that I cannot say for today's films with heavy drone and pedal music, and hand-held cameras..