I think it's hard for people that are into the comic scene to separate the A-list from the B (and C) list, sometimes. They're just too close to the space, and can't see things the way the "general population" sees things. No matter how important he's been in the Marvel universe, even for years and years, that doesn't really mean much.
Let me tell you - as someone that's very much a nerd (huge into videogames, anime, etc etc), but never got into comic books for whatever reason, Iron Man very much is a B-list character. Or, was. Before this movie.
I've never read a comic book IN MY LIFE, but you still pick-up comic knowledge as a geek. Even before the movies, I knew Wolverine's superpower. I knew Spider-Man's origin story. I knew about the death/rebirth of Superman. You just pick this stuff up, even if you don't read comics.
But I literally knew NOTHING about Iron Man. I didn't know his real name, who his villains were, the origin of his suit, nothing. He was B-list, before this flick. No question about it. I'm not even positive I could have picked Iron Man out of a line-up prior to the marketing of the movie.
Also Tony was also all emo when he gets captured to when he returns back. His transition from emo to chauvinistic dude looked like an on/off switch.
