Re: Patrick Stewart & Ian McKellen Return for Days of Future Past
We're getting into semantics, but yes, I would consider Iron Man 3 a sequel to The Avengers. It's a follow-up that tells one more avenue in the story of The Avengers. Whatever word you use, it furthers the story.
I guess what I'm getting at is not the word; it's the fact that we were told The Wolverine takes place after the other films and leads into DOFP. IMO, that's a pretty good hint that the dystopian future continues on from X1-3 and is not a completely alternate reality. Could time be altered once the traveler goes back in time? Of course, but I don't see the jumping-off point as a completely separate dimension/reality/timeline/whatever.