We've been hearing rumors for awhile that there has been talk of the Avengers, X-Men, & Spider-Man all operating in the same giant Marvel Cinematic Universe. Not necessarily a full-blown crossover, but more talk of nods and winks that the 20th Century Fox, Sony, & Marvel Studios universes might not be as separate as most fans thinks.
However, when both 20th Century Fox and Marvel Studios announced plans to utilize Quicksilver in upcoming movies, most reports seemed to indicate the two studios were at odds, and there was no chance of any future crossover.
In a fan Q&A on IGN, Marvel Studios President Of Production Kevin Feige was asked about the possibility of a deal to put Spider-Man, Avengers, and X-Men on the screen together, amd Feige suggested that the door may not be completely closed.
"I would say, not any time soon would we be in a position to team up with other studios who have a few of our characters, because we have so many characters ourselves," said Feige. However, Feige added, " But I would never say never."