The thing is, once MH4 is out as a 3DS exclusive, it's all over. At that point we'll be looking at a 3+ million selling title that's built up a rock-solid install base and Capcom will have no reason whatsoever to rock the boat because those people will keep buying future MHs on the same platform. If Capcom were having second thoughts about committing the franchise to 3DS, the time to act on it would be right now.
This doesn't really make sense. Capcom has always had multi-platform Monster Hunter titles. Even when Frontier hasn't sold anywhere near what the console/handheld versions have, it still has 10 or so seasons of content and support.
I mean, it's quite simple really. When even the Xbox 360 has a Monster Hunter game, then there is no reason why we should rule out a Vita title.
What else will they do with the Portable brand?