At the end of September, director Jon Favreau escaped his "Iron Man 2" edit bay and took a couple of days for an island getaway, traveling thousands of miles to the remote Pacific island of Bora Bora to promote his comedy "Couples Retreat." But as he soaked up the sun and kicked back with co-star Vince Vaughn, his mind was still very much on Robert Downey Jr.'s Tony Stark and how the sequel to one of the biggest movies of last year was coming together.

"It's a tricky phase," Favreau admitted of the sequel, which is expected to arrive in theaters in May 2010. "Unfortunately, it's not like a traditional film where you try to get your cut together and then you try to figure out what's working or not. In the case of a superhero movie, an action movie heavy with CGI, you're turning over sequences and getting shots back. So as we begin to see what the vendors are bringing us, the movie starts to come together."

The new "Iron Man" will introduce a fresh crew of heroes and villains, including Don Cheadle as War Machine and Mickey Rourke as Whiplash. According to Favreau, until he and his team begin to see these characters in completed visual-effects shots, they can't really know what their film will be.

"When we see what War Machine looks like, Iron Man, the way Whiplash moves, the way the action sequences are coming together — so that's one thing we're working on now is we're continuing to create and generate dailies and digital shots for our animated portion, which is in essence the action sequences," the director explained.

While Favreau is already in the edit room putting together his director's cut, and Downey, Cheadle, Rourke and the rest of the cast have finished principle photography, shooting continues to take place. "We're also building CG environments where we're shooting smaller sets with green-screen backgrounds. We're starting to see what that all looks like," Favreau said. "But fortunately I have the performances. Those are all in camera because those are the actors and I just have a great, great cast."

A lot may be up in the air, the director conceded, but one thing he's sure of is that new film will aim for the first flick's edgy attitude, emphasizing Stark's familiar sardonic wit — maybe even taking it all a little further. "There's that great tone and sense of humor from the first one, and I think we upped the ante a bit in this one," he said.

Check out everything we've got on "Iron Man 2."

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