Scripts are just guidelines for Marvel movies, says Iron Man director Jon Favreau, so planning for the future is hard.
Favreau says that the plot of the third instalment will depend on the events of the Thor, Captain America and Avengers movies. There's a snag though, as Favreau doesn't know what those events actually are.
What's more, he isn't sure if the directors of those movies are entirely sure what will happen either. Favreau said that he'd had conversations with Kenneth Brannagh and Joss Whedon, directors of Thor and The Avengers movies respectively, about where their movies might be going, but admitted that the way that Marvel made films made it hard to know exactly what was going on until a project was finished. "The script is one thing," Favreau said, "but when you actually see what you land on at the editing room - especially with Marvel where they film, cut, film some more and shape the film - you really learn as you go."
Favreau has previously expressed an interest in making Iron Man's long-time comic book foe, the Mandarin, the villain in Iron Man 3, but said that he couldn't even guess where the story would actually end up. This is assuming that Favreau actually gets to direct the movie, as Marvel is rumored to be unwilling to pay for his talents anymore, favoring cheaper talent instead.
Iron Man 3 is currently scheduled to hit theaters on May 13th, 2013. Who will be in it, and what it will be about, however, is a mystery.