I'm saddened that "X-Men: First Class" (the best of the X-bunch) director Matthew Vaughn didn't return, but excited that original "X-Men" director Bryan Singer has returned. What's going to be interesting is how so many characters, both old and young versions, will be handled in this time travel saga.
The thing I'm looking forward to the most is if there are any real key scenes between Ian McKellan's older Magneto and the fantastic Michael Fassbender's younger Magneto. Fassbender was, in my opinion, the best thing about all of the character portrayals so far in an X-Men related film (yes, even over Hugh Jackman's awesome portrayal of Wolverine). James McAvoy was also great, and will also likely eat up the scenery with his older, Patrick Stewart-y self.