I was kind of thinking about this due to the DoX relaunch having an X-Men/Fantastic Four crossover mini. What if there's one for Spider-Man? It makes sense -- two of Marvel's biggest cash cows in a crossover with a new status quo. I asked here instead of the X-board because I feel like I'll get a better response from Spider-fans, but I might ask there later too.
Let me know your ideas and we can discuss.
One idea I had is that Spider-Man can be a guest teacher at school in Krakoa. Non-mutants can enter with permission and maybe he can substitute for someone he's friends with as "Mr. Spider-Man". Seeing how Spidey reacts to the mutant paradise would be part of the appeal, as would him playing off all the mutants. There would probably be some kind of mission that forces Spidey to team up with a team of X-Men, because obviously.
What would be your ideas?
Remember, try to fit it in the current X-Men and Spider-Man status quos!