For a long time now, there have been rumours that Fox are planning a crossover between the Fantastic Four and X-Men franchises as they look to mimic the success of the Marvel Cinematic Universe. Producers of both franchises have refused to confirm or deny those reports, but if a team-up is on the cards, it's going to be pretty damn hard to explain. Rumours point to the characters being kept apart for the foreseeable future, possibly because of some complicated legal issues stemming from Fox having bought the rights to both sets of heroes at different times. Marvel could very well put their foot down and prohibit the studio from putting them in the same movie; at least in business terms, that would make sense. Producer/writer Simon Kinberg semi-confirmed this some time ago when he reasoned that both teams existing in the same world wouldn't make sense; why would mutants be hated when the Fantastic Four aren't? That's a pretty flimsy excuse, but with the X-Men exploring the 80s, a crossover could prove to be too complicated regardless of any rights issues.
