Now we know that next May, Tony Stark and Steve Rodgers go to war in Marvel's "Captain America: Civil War". But nobody knows WHY........But I have a theory. You know, how Tony Stark is super paranoid about potential threats to the Universe? Well, How about in Civil War, it is Tony knowing that we could get Alien invasions, So, He wants the earth to be ready, so they sign up to these "accords" as Cap and Falcon talk about in the after credits to Ant-Man.
It would set up Tony's motivation quite well, and makes it that, neither man is "right" or "wrong". Which is what made Civil War: The Comic quite poor in my opinion. Tony Stark was a Grade A jerk in that, At least with this theory, it'd give some...reason for his actions.
Maybe not the most craziest theories out there, But I think that's what's going to happen.