If Iron Man 2 is any indication of what Marvel intends to do with Captain
A shared superhero universe has been the norm in comic books for five decades. Marvel Comics' first, great editor and writer Stan Lee popularized superhero crossovers to boost sales for less popular titles. It worked. Superheroes guest-starred in each other's comic books, superheroes teamed up to battle a global threat individual superheroes couldn't take on alone, first on an ad hoc basis and then more permanently, e.g., DC's Justice League of America or Marvel's The Avengers. (Justice League of America has been in print since 1960 and The Avengers since 1963.) The inclusion of visual and verbal callbacks to earlier events in the same universe, other characters, or even other objects gave knowledgeable readers the satisfaction in spotting sometimes obscure reference while reminding them of the other comic books they weren't reading.