The plot of Days of Future Past is based on a popular storyline from the X-Men comic book, where one of the mutant team from the future time-travels back to the past to prevent an assassination which will lead to martial law and a dystopian future where Mutants are almost extinct.
The fact that the majority of the upcoming sequel will take place over a decade later than the events depicted X-Men: First Class seems to indicate that the JFK assassination won’t be the reason for mutants from the future travelling back to the past to change the course of history, as has been speculated, ever since Matthew Vaughn (who directed X-Men: First Class) said he had planned to include the Kennedy assassination in a sequel, before he left the franchise. What will be the reason? Singer isn’t saying yet.
A ten year gap between the events of both films would make it easier to explain why certain characters are not being brought back, such as Emma Frost (January Jones) or Moira MacTaggert (Rose Byrne). Does this mean that James McAvoy’s Professor Xavier will no longer have his hair?
Thus far, the cast includes…James McAvoy as young Charles Xavier; Michael Fassbender as young Magneto; Patrick Stewart as older Professor Charles Xavier; Ian McKellen as older Magneto; Nicholas Hoult as the Beast; Jennifer Lawrence as Mystique; Hugh Jackman as the Wolverine; Shawn Ashmore as Iceman; Anna Paquin as Rogue; and Ellen Page as Kitty Pryde. The casting of supporting roles is still being done. Since much of the movie will be filmed in Canada, the filmmakers are currently casting some minor roles using local talent from Montreal.
The scheduled release date is July 17th, 2014.