Originally Posted by Thundercrack85
Why would they want Fantastic Four?
As for X-Men, Fox can't afford to give it back.
Marvel/Disney wants to use Galactus & The Silver Surfer from the FF in its cosmic stories. With Guardians of the Galaxy
coming out in 2014, those characters could be an important part of the MCU going forward. Marvel already tried to make a deal to use Galactus and the Surfer in exchange for allowing Fox an extension on its rights to produce a Daredevil movie, but Fox shot them down.
As for the Fantastic Four
themselves, they could bring a lot more to the MCU than just the cosmic characters. The FF are Marvel's first family; it would be perfect to have them and their villains integrated into the cinematic universe. The rights to Doctor Doom, Annihilus, Super Skrull and many other iconic characters accompany the FF. Kevin Feige would probably love to have Reed, Sue, Johnny & Ben back, along with their fifty years of history.