While this is a nonexistent possibility due to Marvel Studios being a money machine for Disney. But DC and Warners aren't in a similar situation. No one imagined Sony would partner with Marvel to produce more Spidey films, nor Disney would be in a position to acquire X-Men/Fantastic Four due to the pending Fox acquisition. However, there are marked examples of DC and Marvel partnering for crossover comics over the decades... Spider-Man and Superman having two separate crossover stories. Teen Titans vs. Uncanny X-Men. Even a Green Lantern/Silver Surfer story is out there.... the list goes on. The main difficulty of doing these crossovers is not just inter-studio cooperation, but who would be the guiding force behind the scenes? Would Feige and Geoff Johns work together or clash? Would there be casting continuity or new faces recast? Which studio would release in North America and who would handle international?