Rich Johnson over at Bleeding Cool just broke this story.

http://www.bleedingcool.com/2012/06/28/big-hero-6-disney-surprise-first-marvel-film/

He did all the work, he should get all the credit.  Head over to Bleeding Cool to read all of the details.

Currently scheduled for 2014.

Damn, looks like I need to do a lot of research on two comic book teams in the next couple days.