Just to point out from the get go, this is all speculation. I'm not aware if anyone has posted something like this before.So don't slate me if this has already been touched upon.
Now we all know about the grey area concerning characters such as Scarlet Witch, Quicksilver, Kree, Skrulls, et.c because of their long term association with Fantastic Four/X-Men and at the same time Avengers. Could it be possible for other characters to be built up in such a way(in the comics)that they could be used in both Marvel Studios franchises and Sony/Fox franchises?
Spider-Man and Wolverine have been consistently associated with Avengers comics for about eight years now, joining in 2005. Isn't that roughly the amount of time ago that Marvel established their own studio? There is now an Uncanny Avengers team with focus on using multiple mutants on the team. What I'm getting at is if Marvel carry this on long enough, could they potentially use these characters with slight revisions in their Avengers based franchise?
Now I'm not saying they should or will do this, though it does seem to me that they may be playing a subtle game here.
Anyways...sound out your thoughts in the comments below.