Though many may expect that Robert Downey Jr just might be a "featured attraction" in Civil War, this is far from the case. The actor is taking on this assignment in lieu of Iron Man 4, and if reports are to be believed, he will be pretty much co-starring in the movie, shooting around 30 or 40 days of material. This is obviously fantastic for anyone desperate for another Iron Man fix, as long as Stark doesn't end up overpowering the movie and stealing Cap's thunder. Still, above all else, it's clear that with the Civil War storyline being the narrative thrust of the film, Downey's part is no mere cameo: he is going to be a huge part of what's going on, and it shouldn't be any other way.