I said this a lot, but I'm sticking with this point of view. Vita has a software problem. Not a lack of software problem like most Vita fans like to say people are claiming. "Vita has no gaemz" is said most by Vita fans than anyone (it's actually doing quite alright in number and quality). But it has a software problem, nonetheless.
3DS won't lose MH, but if Sony allow it to launch an exclusive MH4 in japan, then it's almost over. 3DS will become a err... monster! No sane developer will develop a game for a system with 2 million user base (that number is so far away by sales trends) than to one with 13-15 million.