Okay, so this title is troubling. The Terrance Howard Syndrome(he didn't return from Iron Man because of his wanting more money) has now reached the Avengers cast. Here is source.
So what do you think? I think that those 2 are not truly necessary for the roles as other people could fill the roles just as easilly if not even a little better(especially for Thor, I even have someone I wouldn't mind replacing him in mind).