Since I'm known for my glee in covering all things Iron Man I'll fill you in on the latest published interview with Jon Favreau. It's a couple of months old from the timeline mentioned in the interview and he doesn't divulge much. For the record I think that's a good thing... if there's one movie I don't want to be to spoiled about before watching it this is it, although that makes it awfully difficult to cover here on the site. :-)
Anyway, as far as I'm concerned the most significant bit of info mentioned is that Favs is apparently not shooting for a 90 minute run time, which was feared by many. He states that the length will be:
"Probably between [an hour and 45 minutes and two hours]. I don't think it should go much longer than two. We have to see how it plays."
Personally, I'm hoping for closer to two hours. Iron Man will play more like a action/spy film than a comic book movie and therefore could use a bit more screen time IMHO.
He also pretty much confirmed that there will be a new commercial for the film aired during the Superbowl (Tivos at the ready!)
As to whether Hillary Swank and/or Samuel L. Jackson will appear, he was pretty tight lipped and would neither confirm nor deny. Same went for any appearance by the Hulk (which I think is a bogus rumor, BTW). He knows how to handle the online media: If you give the same response to every rumor anything is possible, or nothing at all. :-)
He also said that he does have a very small cameo that could grow into a larger role. If that doesn't say "Happy Hogan," I don't know what does.
Iron Man opens on May 2nd, 2008.