Director Bryan Singer tweeted out the first teaser photo of Patrick Stewart as Professor X in X-Men: Days of Future. The photo came with the following caption...
Picture before picture. Tomorrow it begins.
The film also stars Hugh Jackman, Ian McKellen, James McAvoy, Jennifer Lawrence, Michael Fassbender, Anna Paquin, Ellen Page, Shawn Ashmore, Peter Dinklage, Omar Sy, Halle Berry, Daniel Cudmore, Fan Bingbing, and Boo Boo Stewart.
Based on the comic book storyline "Days of Future Past," which ran in Uncanny X-Men #141 and 142 back in 1981 during Chris Claremont and John Byrne's run and 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.
X-Men: Days of Future Past is set to be released in theaters on July 18th, 2014.