Re: Characters you'd like to see in future Avengers movies?
Sure they aren't.
The Avengers are known for having a rotating roster. As long as Iron Man or Cap is on the team, everyone else is fair game.
Besides, I'm really hoping Tony dies in A2. It would be magnificent storytelling, as his death was foreshadowed in the first film, and it would really get across just how dangerous Thanos is and back up his love of Death, and would immortalize him in film history.
Tony doesn't have to stay dead. As I've said before, they could just bring him back in A3 ala Star Trek III with Spock.