Robert Downey, Jr. and Jon Favreau on Iron Man 2

For me, there were so many different bases to run. The screen test and all that, and then [director] Jon Favreau calling me to tell me I got the job - it wasn't even the beginning, although I'll never forget that day. And then by the time we were rehearsing and working with the writers and playing around, I kinda had a sense that maybe we were on to something just a little bit different. And then by the time we were up in Lone Pines, shooting his escape and landing in the sand dunes, I thought, Wow, this is actually looking kinda epic and cool.... But then Comic-Con really felt like we were halfway to something that might work. And then Jon and I were doing our world [promotional] tour, and really saw an audience that was just folks. You know, when we brought it to the military base in Korea, and we saw people showing up and really digging it, I thought, Wow, we got to really start pushing hard. Then we did Europe, and then the U.K., and then New York.... But all the way throughout the world tour, Jon and I would find ourselves waking up on these super-long intercontinental flights, and we just started brainstorming about, you know, if this goes well, where might we take it? And what worked in this one, and what does the audience want to see, and how do we continue this guy's journey? What is it about him, and what is it about the way Jon directed this movie and the way we created the character that people were so overwhelmingly excited about? So we had a lot of heart-to-hearts.

We've been speaking informally about it, and in concept we would all love to work together again. But I found out about the announcement last night, so it's not something that - we would definitely love to collaborate more with the sequel. There's no formal arrangement yet, but in theory we would all love to see it happen.... There's definitely a lot of ideas that we all have now. This type of movie is based on serialized materials, so it lends itself very easily to [many different sequel possibilities]. There's definitely a level of enthusiasm from myself and the cast to tell more stories.

It's very difficult to keep these franchises from running out of gas after two [movies]. The high point seems to be the second one, judging by history: If you just look at the consensus in the reviews, you see that X2: X-Men United and Spider-Man 2 are sort of seen by the fans as the sort of high point of both franchises, though I don't necessarily agree with that. But to be able to fold it into The Avengers is something you just couldn't do in another studio, and I think what Marvel is about is stuff you can't do at a bigger studio. They gave me tremendous creative freedom; they gave me tremendous freedom in casting, at the end of the day. Even though there was concern, they ultimately backed a decision [to hire Downey to play Tony Stark] that I don't think a studio would've, and now they're benefiting from having that nimble creative team. And that's, honestly, the most attractive aspect of working with them again.