Just read this on Bleeding Cool:
Now, we don’t think Stark is going to pop up in Thor 2, and we don’t think he’ll pop up in Captain America 2 either but it’s a given that he’s going to be a core part of the Avengers 2 lineup, right?
Well, we were taking this for granted. Until we were told not to, by somebody we can trust.
Don’t take that for granted.
…they said. Literally.
We tried to clarify if this means he won’t be in the film, but we were told:
That’s the wrong question.
And that’s as far as it’s gone. So far. I think perhaps we were asking questions that were too closed… too binary.
That's...surprising. I wonder if it's more about contract negotiations than anything else.