X-Men & Fantastic Four Team Up

SFX Magazine had an interview with Mark Millar, comic book writer and the overseer of Fox's comic book movie properties.  Joe Steiner asked, "Will the upcoming reboot of the Fantastic Four share a universe with the future X-Men films?"  The following is Millar's response:

Without question I think you have to see some of these guys showing up in each other’s movies. I think the most exciting thing in superhero movies, until The Avengers came along, was when Nick Fury showed up in Iron Man. Even though it was a guy with an eye patch it was really cool – and I expect we will see more of that.

Mark Millar (@mrmarkmillar, unverified) then followed with two tweets stating,

I keep seeing 'news' that X-men & FF movies are crossing over.  No, they're not.  They exist in same universe but movies stand alone.

Note to the web journos: FF & X-men are NOT crossing over.  Existing in a shared universe does NOT mean a crossover movie, excitable ones...

What can we discern from all of Mr. Millar's comments?  The Fantastic Four reboot will be a stand-alone movie.  X-men: Days of Future Past will be a stand-alone movie.  So, how is it a shared universe?

Fox will no doubt want to capitalize on the success that Marvel has had with The Avengers.  I see both movies having stand-alone films and then the movies will start bleeding into eachother.  We may even see a teaser scene for Fantastic Four in the X-men: Days of Future Past credits.  Or we may see a teaser for the next X-men movie in the Fantastic Four reboot. 

I don't think that you can have a "shared universe" without having some crossover at some point.  It would take away from the story if you included X-men characters in the Fantastic Four reboot.  You have to introduce the characters first.  You can't just say that it is a shared universe without showing that somehow.

I think that we may see these characters showing up in the other's movies someday.  It would be in Fox's best interest to make the most with what they have, especially as we see changes in actors for some of the main X-men characters.  Plus, I just want to see a Fastball Special with Thing and Wolverine.