I hope it happens very much, but it will definitely be a tough negotiation for Marvel. Hopefully, the fact that they are considering it, and that it leaked to the public and fans really want it, could make Sony accept a deal.

The issue is that Sony is making their own spider man universe, and allowing him to appear in other movies, would mean that they will have to have that continuity themselves. However, if Andrew Garfield was indeed let go, it could ease the process a lot.

In my opinion, it would be a great business decision for Sony. Marvel will take care in some way of the success of spider man and then sony could take advantage of it to continue making movies, but with the character better stablished.

Sony hasn't done a great job with spiderman so i think it's a great opportunity for them, specially since recently, everything that Marvel touches turns into gold.