During an interview with Avi Arad, Arad stated that the rights to the Kingpin were on "loan" to FOX for the Daredevil movie and now they have returned to Sony. So, apparently, film rights can go on "loan" to other studios. This bypasses some problems that might show up with the legal issues of using the characters. Put the rights to the character on loan.
So, say Marvel wanted to use Spider-Man and Sony was willing to let them use him. Sony would give them a term for how long the film rights would be in Marvel's hands for the movie and, at the end of the term, the rights would transition back. The selling of the rights would probably double the costs of the movie's production, which leads to yet another thing...
How would Marvel at all benefit from having Spider-Man in the MCU? A lot of people make the argument that the movie would make just as much money from it with Spider-Man than without him. The answer, however, is far more complicated than that.
During a deal with Sony, Marvel (Disney) reacquired the merchandising rights to Spider-Man. Sony, however, bought the involvement of Marvel Studios for their films. Marvel Studios now has a higher say and stake in the movies than ever before. Merchandising for both franchises would explode in terms of toys with Spider-Man and the Avengers sharing a movie.
The second thing is, by that logic, a sequel to a movie wouldn't make more money than the original. But, more and more, that is beginning to not be the case. I guarantee that the Avengers 2 will make more than the first one just as Iron Man 2 made more than Iron Man. However, would Spider-Man being in an Avengers movie actually pay of Marvel Studios?
Perhaps. The biggest problem is that they at least need to make 200 million more dollars off the movie than the original Avengers to pay for it and to make it at all worth it. However, as we don't know what the reaction would be to it, we just don't know what the result would be. But increase in merchandising (where most of the money off the franchises exist) is inevitable.
Now, the other side of the argument is, wouldn't that hurt Sony or FOX? Well, not necessarily. Let's continue to use Spider-Man for an example. When the Avengers 2 starts shooting, the Amazing Spider-Man 2 is in post-production, meaning that no new sequel material is being prepared. The Avengers 2 shooting dates will be between February and the end of 2014. However, the Amazing Spider-Man 2 did not begin filming until this year in February. Meaning if Sony wants to maintain its two year break between sequels, shooting for the Amazing Spider-Man 3 could, logically, commence in February of 2015. Now, getting into film rights is complicated and nothing I can do easily. But I'd assume a deal would be made to actually be filming the character. Sony wouldn't be filming with the character during post-production and they wouldn't be filming with him during the pre-production stages of the Amazing Spider-Man 3.
How would this benefit Sony? Well, they'd obviously make money off of whatever Marvel Studios would pay for the temporary rights for the film (money that they wouldn't have acquired in the first place since this is when the money is usually put in). However, with the Amazing Spider-Man making about 50 million dollars less than the least popular of the first trilogy, the Amazing Spider-Man could use that brand recognition that Iron Man got. Spider-Man is an extremely popular character already and, if you throw him in the Avengers, brand recogonition for the MCU soars and Spider-Man could potentially be the biggest solo film for all of Marvel. While this may not seem to help Marvel Studios, it would because of all the merchandising rights.
Finally, a crossover, at least between Sony and Marvel Studios, would be beneficial due to the output of movies. Kevin Feige stated that Marvel Studios can only afford to make two movies a year. However, with Sony, Sony can make another movie every other year. Now, with the horrible job that Sony did with adapting Ghost Rider, I'm not sure you'd want to give those rights back but giving Sony the rights to properties like Daredevil would allow for these character to easily show up in a little mini-pocket universe of vigilantes in New York without any of the rights transitioning. Now, I can't see that happening but it is always possible. This would increase output of movies and would beat the amount that DC would be able to output since they only have one studio producing these movies. Use the division to your advantage!
Fox, however, is a different story. Marvel Studios hasn't reacquired any merchandising rights and Fox seems unwilling to cooperate (unlike Sony who has been trying to jump into the action). With the current state, I doubt Marvel Studios would consider it a low enough risk to bargain with Fox than it would be worth and thus would let them continue to make their own movies. So I find it less likely than ever that Fox and Marvel Studios will play nicey nice and find a place for the Fantastic Four or the X-Men in the MCU.
With Sony, however, even if Marvel keeps the rights to Daredevil, there are other avenues that can be explored. Since Kingpin is a crucial part to Daredevil now, Marvel would probably go onto the same loan. However, once the rights transition back to Sony, Sony can use the Kingpin and use the same actor to tie it in. Obviously skylines being shared isn't too much to ask (Latino Review scoop about OsCorp Tower almost being in the Avengers). Along with all of the above, it would be in the two studios best interest, given their current position, to do what needs to be done. And all evidence seems to be pointing in that direction.
Now, if you don't agree or would like to share your thoughts I would love to hear it. Sound off and good day to you all.