At an interview at the 2013 Galway Film Fleadh, Zachary Quinto revealed the plans for the filming of the next Star Trek movie: He also claimed that J.J. Abrams was still hoping to direct, even with his existing Star Wars commitment. http://buzzhub.wordpress.com/2013/07/12/zachary-quinto-exclusive/ Original Source was from io9.com
Go over to Rotten Tomatoes, and there's a story that the date for James Cameron's second "Avatar" movie is going to be December, 2016 (with two more after that in December 2017 and 2018). With "Star Wars" in 2015 and "Avatar 2" now officially a Christmas 2016 movie, a summer 2016 release for STIII is even more logical. Given the timetables of the other two Trek movies, that would mean shooting in the first quarter of 2015, I'd guess. That gives them all of 2014 to come up with a dynamite story and script.
But would the fanbase prefer a september release, or a june release? With september being the actual anniversery of TOS. Personally, I couldn't care less, as long as the movie itself is good (that remark is going to be made fun of a lot I'll bet ).
What is interesting is that they haven't yet announced a release date for new Star Wars movie. SW movies are traditionally released in May. And Disney already has the new Avengers movie for May 2015. Would Disney actually release their 2 mega-blockbuster movies in the same month? I wouldn't be surprised if Star Wars VII gets pushed back to summer 2016 which would make things very interesting.
Summer 2015 will be a turning point in Hollywood. So many blockbusters wannabees and not enough dollars for them all. There will more flops than expected.