I wondered if there was concern about the lack of mutants in the Marvel movie universe and now SHIELD tv show separating the X-Men from the Marvel universe. I was lamenting the fact that "mutant" can't be used on SHIELD, and a colleague told me he wasn't aware that X-Men were part of the same universe as Avengers. As more people's entire knowledge of the Marvel U is from Avengers movies and tv show, that seems like it's going to become a problem.