UPDATE: Deadline's latest news is that Fox sources are denying they are in negotiations to trade pivotal supporting characters in such a deal when they are actively looking to kickstart the FF reboot and would actually be willing to lose Daredevil - though co-financing may be an option). It's clear whatever IS being discussed may not be plain sailing... which outcome benefits Marvel/Disney the most?
Marvel have done spectacularly well at the box-office in recent years, but those with more than a causal interest in blockbusters will be aware that their vast catalogue of comic-book characters are not compeltely under their own control. For instance, the rights for such iconic, figurehead characters such as The X-Men and Spider-man are owned by Twentieth Century Fox and Sony respectively rather than Marvel Studios, which was a company created later - and after the rights had already been sold. It is for this reason that any significant cinematic crossover between, say, The Avengers and The X-Men is unlikely to happen (though there was talk of seeing an OsCorp building from the revamped Amazing Spider-man in The Avengers, something that never made it to the finished version and there is a grey area concerning some supporting characters that arguably fit into the mythology of more than one franchise).
However, news is being reported in trade-paper Variety, that some deals are being considered behind the scenes which might mean some changes to that arrangement.
Before anyone gets excited, superhuman team-ups beyond the Avengers line-up are still highly unlikely, but there could be a trade-off of rights on the horizon. Twentieth Century Fox has spent a considerable amount of money and time on a Daredevil revamp, a project that seemed somewhat stalled with director David Slade no longer onboard. However if a big-screen version of the famous blind lawyer/vigilante isn't in front of cameras by October 10th, then the rights revert back to Marvel. Fox apparently wants to make a deal with Marvel to extend that contract to enable them more time to get the project ready to film - possibly with Joe Carnahan (Smokin' Aces, The A-Team, The Grey) and perceived as a more Frank Miller-esque '70s-styled hardcore thriller'.
In return, they could be willing to hand-off the rights for supporting characters such as The Silver Surfer and Galactus back to Marvel. As 'Phase 2' of the Marvel Studios film initiative kicks into gear with a more 'cosmic' remit, this could be an enticing propostion. The deal, if both sides can make an agreement, would make pragmatic sense... though there's a Fantastic Four revamp planned (to be directed by Chronicle's Josh Trank) there's no indication that Galactus or the Silver Surfer are needed for that and the advantages of gaining time for the Daredevil project would be advantageous.
Films with comic-based source material are proving box-office catnip and with hundreds of characters and a range of styles and tones, they can be tailored to many different demographics. With the back-catalogues currently available, it would seem that even in the event that a deal isn't struck on this particular issue, such deals may have to be considered down the line... hopefully in a way from which both studios and audiences can benefit.