A source close to Fox had this to say.
"He's definitely a big part of Fox's whole plan for a big X-Men universe with spin-off movies. The Avengers really is the template here
Will he show up in Days Of Future Past?
"I won't say too much about that. You'll just have to wait and see."
Director Bryan Singer has played coy with the idea in the past, hinting that the 5,000-year-old human mutant may show up in X-Men: Days of Future Past.
One of the very first mutants, Apocalypse is both thousands of years old and a monstrous tyrant that has been a longtime foe of the X-Men. Apocalypse believes that only the strongest (whether mutant or superhuman) should survive. His body is a mix of organics and powerful celestial technology.
X-Men: Days of Future Past was released May 23rd, 2014 and stars Hugh Jackman, James McAvoy, Michael Fassbender, Jennifer Lawrence, Halle Berry, Nicholas Hoult, Anna Paquin, Ellen Page. The film is directed by Bryan Singer.