I think it'll either be Hulk, the traditional Spidey/Hulk team up or even better, Cap. Imagine a film where Spidey gets his butt handed to him in hand to hand and Cap shows up to train him and in turn, they learn that aren't so different. It would have a Rocky kind of feel and in the end it has them both face off like…

My guess is that Luke is actually determined to keep any new Sith or Jedi from returning. The best balance that can be had in the Force is zero users.