The very idea of a Star Wars film not being composed by John Williams, especially the beginning of a new trilogy meant to erase the stain of those prequel films, is just insane. Thankfully he is indeed going to compose Episode 7. That is a good sign for these films.
As much as I hate Disney buying Star Wars and Lucasfilm and making another movie, John Williams is too good to not have in a Star Wars movie. He is the President of Star Wars music, and any Star Wars episode without him is a lot worse than one with him.