Iron Man 3 screenwriter Drew Pearce recently did an interview with SciFiNow in which he talks about what he knows about Joss Whedon's Avengers: Age of Ultron.
On the ending of Iron Man 3:
"We take his arc reactor out, but I think we also make a pretty definite statement that he is Iron Man. And although Joss isn't part of the process as such, he saw all the cuts of the movie, so I've got to assume he knows exactly what he wants to do with Tony in [The Avengers: Age of Ultron] and how we've left [Tony Stark] is going to help that, not hinder it."
On the big Comic-Con title reveal and the scale of the film:
“Obviously, Age of Ultron suggests that in Avengers 2 there will definitely be some level of, if not giant evil robots, then definitely a robotic or artificial intelligence entity. I may or may not have been excited about it for a year. Not every aspect of Phase Two is planned already, but Joss has been thinking about it for a year and Kevin has been thinking about what Avengers 2 does since the first film. The scale I think they're going to reach for is going to be truly epic, which is incredible when you consider how epic Avengers was. But on a character level the story will actually be smaller, or at least more intimate. It's hard to put a list together of all the things Joss [Whedon] is good at as a writer, but definitely in the top five would be dealing with the shifting dynamics of a large group of characters."
On Whedon's style of creating a family then tearing them apart:
"The core of Avengers will still be our Avengers. There will, of course, be other characters in the mix, but I think what Joss is really good at is creating a family and then pulling them apart, and to that end he's got so much more to do with the family he established in Avengers. So I suspect that the first port of call in that movie will be kicking the shit out of those characters to see how they cope as a group."
On Tony Stark being the creator of Ultron:
"There is a hell of a lot of rumors, though. Ultron may be something that appears in Guardians of the Galaxy, or it might appear in the Thor universe. I've read a lot of stuff online, and I don't think anyone has got close to the real plan yet."
Avengers: Age of Ultron doesn't come out until May 1st, 2015, but I have no doubt it's going to be freakin' amazing!