We all know that a successful Monster Hunter can make a portable. The PSP exploded after each subsequent Monster Hunter launch, and the Vita is currently suffering in part for a lack of the franchise.
Nintendo seems to be ahead of the game in locking down Monster Hunter 4 for as long as it can, as it is distributing the 3DS game in Europe (Capcom is still publishing). Nintendo will apparently be responsible for the sales, marketing, PR, and distribution of the game in Europe and Australia.
There is precedent for this partnership (through games like Resident Evil: Revelations), but I'm expecting big things out of this Monster Hunter release.