The lost sales would cost Capcom more than Nintendo would theoretically give to Capcom. It's gonna sell a bucket load on the 3DS (and if the rumored Vita version is in the works) which will make Capcom a pretty penny.

LOL, exactly. This game is so chained to portable play at this point that taking it off handhelds would cripple the franchise.

If Nintendo made Monster Hunter 4 exclusive for Wii U, the Wii U would sell in Japan and sell the same as it's been everywhere else. There isn't a big fanbase for Monster Hunter anywhere else.

Monster Hunter's appeal is its portability, so this is a stupid idea.

The Wii had MH3 as "exclusive" for a good while and it resulted in no where near the same sales or impact as the portable PSP games.

Wii U needs franchises that sell home hardware and Monster Hunter, by and large, doesn't do that.

It would certainly help their situation in Japan I could tell you that much. Anyways a single exclusive would only be a temporary fix unless there are other software to support any upward momentum. It is fortunate than that the Wii U is finally going to be picking up some nice exclusives this year and next. Along with a couple of compelling indie games the Wii U should fix the lack of software (only 1 major release during that time) problem that plagued the system for nearly 8 months after launch.

poor sales of game in exchange for 10k or so extra console units sold

Isn't that 3ds exclusive?

Yeah I thought so too, but I think it will be more than 10k console boost!!! I would at least give 100k boost as Tri helped the Wii gain more than that. But seeing that Nintendo is finally going to release quality software it maybe sustainable if MH4 came out to the Wii U as well.  They really need a big 3rd party exclusive like KH, Tales, or FF for it to completely turn the Wii U's momentum with a single software.

It would pretty much kill the franchise

Although the wii u would recieve a nice little boost

it would help WiiU a lot, it would also kill the series