Last we heard it would be summer. My DH and I took the backstage magic tour last month and watched them working on the ride vehicles. They are having some problems with them that could delay the opening. Disney isn't saying exactly when it will be up and ready. I think that is because they don't really know. It is a very complicated ride, but will be well worth the wait I am told by cast members(and they get to try it out first!).
Laura