Call this a rumor if you will, but remember Comicbook.com was the very first site to confirm The Mandarin was the villain in Iron Man 3, back when most were denying it. And while still unconfirmed, we were also the first to report Iron Man would play a role in Guardians of the Galaxy, back before it became the in vogue thing to report.

To be fair, this rumor has been making the rounds on the Internet for awhile, but we have reason to believe that a giant Marvel Cinematic Universe is in the works. Disney has had incredible success creating a movie universe for The Avengers, but other major characters like Spider-Man, X-Men, and the Fantastic Four reside with other studios.

Having seen the success of The Avengers, Twentieth Century Fox has realized the value of a cohesive universe, and they hired Mark Millar to steer them in that direction. Sony has also been trying to build out the Spider-Man universe with multiple villains and a possible Venom spinoff.

However, Sony is basically working with one central character to build their cinematic universe, and Fox is working with only two teams of characters. With Disney, Fox, & Sony each building their own separate universes, fans have no hope of ever seeing Spider-Man join The Avengers or the X-Men and The Avengers do battle.

Or do they? Last year, rumors ran rampant that Sony’s Spider-Man would have a cameo in Disney’s The Avengers. While the rumors ultimately proved to be false, it got the Sony executives thinking about if they could leverage the success of The Avengers to help the reboot their Spider-Man franchise.

When an online journalist recently wrote about how Marc Webb was building his own Spider-Man universe, Marc Webb tweeted back, “Think bigger.” So what would be bigger? Well, one answer is a universe where Spider-Man co-exists with The Avengers. It opens up a plethora of possibilities from small cameos for cross-promotion to cohesiveness between the separate movie toy lines.

Word is that Marvel and Sony have a good relationship, so the possibility of them working out a mutually beneficial deal is stronger than ever. But what about Fox? Well, with Mark Millar coming on board as a creative consultant to build Fox's version of the Marvel movie universe, it also strengthens their relationship with Marvel. And here's what Mark Millar told SFX about what he wants to see. Mark Millar said, "Fox have said that they want to build a cohesive universe and I’d personally like this to work in complement to the Marvel one. It would be cool if these universes didn’t contradict each other so if you went to see Spidey, The Avengers, the X-Men, etc, as a viewer you would have no idea that all three are coming from different studios. I’d love to make it look like they’re all just happening in one place."

The key all goes back to the success Disney has had with The Avengers. Fox and Sony could stand to benefit from The Avengers movie success, while Disney could stand to benefit from the other merchandising that comes with having multiple strong movie franchises. Now as far as anything like Spider-Man actually joining The Avengers, we aren't expecting it, but look for other things in upcoming Marvel movies to establish everyone is playing in the same universe.