Now that I've seen Iron Man 2 (you can read my review here), I'm going to try to be wary of spoilers, but I think it's fairly common knowledge that Tony Stark's dearly departed dad Howard Stark makes an appearance in the film. The elder Stark, of course, was the one who founded Stark Industries way back when, and it's in his shadow that Tony has built the Iron Man suit and tried to continue the solid company name while being a bit of a disaster himself.
It also shouldn't be a spoiler to reveal that there's a lot in Iron Man 2 that sets up the upcoming Avengers movie, and putting two and two together, MTV asked Jon Favreau if Howard Stark might play a role in another one of the Avengers lead-up films-- like, say, with his contemporary Captain America? Favreau's answer, while he probably isn't in on the script process of Captain America directly, was pretty much a "Yeah, duh." His actual answer:
"Yeah, because he was around then, 'Captain America's World War II," he explained. "It wouldn't be that same actor, probably, because he would be much younger. But he was starting out during that time. Howard Stark was involved in the war effort much like Howard Hughes."
It's kind of a bummer that the actor would be different, since Howard Stark is played by Mad Men's John Slattery in the film, but otherwise this continuity between Marvel films is a good thing. I have my own feelings about the way in which The Avengers is eating up all these individual characters, but I'll save that for a rant sometime in 2012.
