According to returning director Bryan Singer,
X-Men: Days of Future Past will utilize 3D technology. Now whether the film will be entirely 3D is another story (but we hope it is). There are certain aspects of the film that can be told beautifully through the art of modern 3D technology.
He's certainly pulling that off, though he's dropped a pretty suggestive hint when talking about the motion-capture technology used in Jack the Giant Slayer to create the giants, saying "I'll probably use some of the motion-capture technology for certain things [in Days of Future Past]." He also confirmed, for the first time, that he'll be using his lessons in 3D from Jack on the next X-Men film as well: "And of course the 3D technology. I'll be shooting native stereo on X-Men."
Source:
CinemaBlend
