Marvel has set the new X-Men movie for a July 2014 release date, but nothing is known about what the movie will be about. Ain’t It Cool News was alerted to a MPAA name registration by Fox for “Days of Future Past”, which could mean they are using that as the basis for the next movie.
As the classic story is set in an alternate timeline, they could use it as a way to reboot the series. But Fox has to be very careful with this, as along with the Dark Phoenix Saga, Days of Future Past is one of the most beloved X-Men stories of all time. It affected the mythos for a long time following it, and if Fox fracks this up; they’ll never be forgiven.