Microsoft is most likely, only by process of elimination. I don't see them jumping at this, just that Sony's pretty much already getting something very much like this, from Sega, as exclusives, and Nintendo isn't going to touch a project like this (overly expensive niche mature game) with a 10 foot pole, they only moneyhat titles that would really help the platform (like Monster Hunter Tri, Tales of Graces, Samurai Warrior 3, etc.)
Monster Hunter: pissing me off since 2010.