Renner has already said he doesn't die in AoU. And I don't really think they will kill anyone off anyone from the first film either... if for no other reasons than because 1) Whedon took enough flak for killing off Wash and Book in Serenity and 2) MCU deaths are pretty much meaningless anyway.
I'm very curious to see what they will do in Civil War; they have different characters in the movie-verse vs in the the comics at the time of Civil War. Not to mention, they've gotten SHIELD in a very new place. (Just taking Hawkeye for one, he was dead during the CW story like (see point 2).)
And I'm not sure people that anyone wants to really see the Civil War story line end how it does in the comics; it would seem sort of Orwellian in this political/social climate for that.
Maybe I'm mis-remembering; but even though Cap did die around the time of Civil War, he and Iron Man don't actually fight to death. Cap surrenders in Iron Man when he realizes that he's the "bad guy" in the eyes of the people, and is then assassinated at this trial, right? (I need to read it again - the story is great!)
Having it work out where personal freedom surrenders to government control, *especially* after revealing that Hydra has been running SHIELD all this time doesn't feel right. I need to work through my back log of Agents of SHIELD and Agent Carter, but I still think that it shouldn't go that way.
I'm not sure how they will do it. I have a lot of faith in Marvel studios; every time i've doubted them, they have proven me wrong in a BIG way....
except with Natalie Portman.... just saying. (maybe its just because I don't like her in anything. but I thought she almost ruined Thor. And she *didn't* ruin Thor 2 so I forgave her a little.) But I still think she had negative chemistry with Hemsworth.
But for everything else, I'm pretty much willing to follow them anywhere....even if they want to kill people off. But I hope they don't.