Since MHwii happened with tri, it seems that a wiiU version is very likely. The architecture is similar, so that should be a major advantage for the teams to just build onto that base of knowledge tri had.
And, as an added bonus, tri did very well on wii - in terms of sales - and people kept playing. Now, add to that the notion that most dedicated gamers on wii were tri buyers and are most likely to buy the wiiU, they'd be silly not to develop for the wiiU...

