There's a short video interview with Robert Downey Jr. over at IESB.net where he discusses his take on the character (arms manufacturer who becomes conflicted about what he does) and how it's going with the armor:
"We're nailing it, we're really working our asses off."
Rope of Silicon has some comments from Terrence Howard who will be playing Tony Stark's best friend Jim Rhodes in the movie. He mentions the War Machine armor and how it won't make an appearance until the second film (depends of course, on the success of the first... a trilogy is planned). He talks about how his character will be envious of the power that Stark wields while wearing the armor.
There's also an interview with one of the writers, Mark Fergus over at MoviesOnline where he talks about the comic book vs. "blank slate" approach:
"It’s kind of both approaches. It’s the guys who are the Marvel guys. There’s a tremendous motherload of history and detail, and being respected and being considered from the whole history of the project – from creation to yesterday. And then there’s also a tremendous opportunity to look at it, from the outside, as a story that needs to do certain things, and to find out what else could be done, and to not let anything be off limits. It’s kind of the best of both worlds which I think will be great for the fans, but it’s also not going to be just stocking that cage like it has to follow everything because the comics evolved, too."
And finally there's a photo of Gwyneth and Robert from the lot over at the Iron Man set that gives absolutely NOTHING away (from ComicBookMovie.com):