Kinberg is first asked about the possibility of having a crossover between the two. He says anything is possible, but lets it be known that the two basically exist in two different universes or dimensions.
Kinberg says if mutants existed in the Fantastic Four world, then the Fantastic Four wouldn't be that fantastic.
Likewise, Kinberg says there are no celebrity superheroes in the world of the X-Men.
The good news happens to be that Kinberg hints X-Men: Days Of Future Past changes the history of the X-Men universe. Whether that means the two can co-exist remains to be seen, but his next comments about the Fantastic Four can be looked at as both troubling and promising.
Regarding the Fantastic Four, Kinberg says, "This Fantastic Four movie is in some ways a reboot. In other ways it's a standalone origin story. By the end of the movie, we don't call them the Fantastic Four. They are not celebrity superheroes. The tone of the movie is much more grounded, real and gritty; more in the direction of Chronicle then in the direction of the original Fantastic Four movies. It is really about how four, and in some ways five - with Victor von Doom, how five people go from being normal people in the world to being transformed when it first happens to something abnormal and then by the end sort of super human."
Previously, Kate Mara also let it be known that there might not be any costumes in Fantastic Four as she hasn't tried any on or participated in any pre-production costume designs, which Kinberg's above comments seem to verity.
"Fantastic Four" has a June 19, 2015 release directed by Josh Trank starring Miles Teller as Reed Richards, Michael B. Jordan as Johnny Storm, Jamie Bell as Ben Grimm and Kate Mara as Sue Storm.