Re: Who would you let Joss Whedon kill in Avengers 2?
One of the reasons that the Coulson death worked so well (and really HAD to happen) was because the audience had come to know him so well. I can't currently think of anyone I know that didn't like that character.
His death in The Avengers was not just an emotional turning point for the characters, but for the audience as well.
I just don't think we've built that kind of attachment to Hawkeye yet. The same can be said for Maria Hill.
I would agree with what I saw someone else on here state: Iron Man is actually a logical choice. However, I think that if they were to do that, it would have to come in The Avengers 3 (assuming that we get three movies).
Iron Man is, from my understanding, by far the fan-favorite character among general audiences (by 'general audiences' I mean people who have little to no knowledge of these characters outside of the films). I think that killing him off in the second movie would alienate a lot of movie-goers before the third.