X-Men: Days of Future Past director Bryan Singer tweeted out a casting board showing us who's officially been cast in the film so far. It also shows that their are six open slots that have yet to be filled.
Cast members confirmed for the film so far include Hugh Jackman, Ian McKellen, Patrick Stewart, James McAvoy, Jennifer Lawrence, Michael Fassbender, Nicholas Hoult, Anna Paquin, Ellen Page, Shawn Ashmore, Peter Dinklage, Omar Sy, and Halle Berry. There's two more cast members that have also been added to the film including Boo Boo Stewart (Twilight) and Chinese actress Fan Bingbing (Battle of the Warriors, Double Xposure). There's no word on who they will be playing in the film though.
The script for the film comes from Simon Kinberg and it was inspired Chris Claremont and John Byrne's comic book storyline that ran in "Uncanny X-Men" #141 and 142 back in 1981. "Days of Future Past" introduced the idea of an alternate future for Marvel's mutants that grew out of the Brotherhood of Evil Mutants killing an important senator, leading to a future where all mutants are hunted by Sentinels.
The movie is set for release on July 18th, 2014!