Let me open up with a list here, with the names of the largest new Nintendo franchises per system, and the sales of the best selling title in said franchise:

NES: Super Mario 40.2 millions

SNES: Donkey Kong Country 9.3 millions

N64: SSB 12 millions 

GC: Animal Crossing 11.9 millions 

Wii: Wii Sports 81.4millions

Wii U: ????

Game Boy: Pokemon 31.7 millions

Advance: -

DS: Nintendogs 24.5 millions

3DS: ????

As you see, every Nintendo system with the exception of the GBA have spawned a new, huge franchise (in terms of sales, and most of the time quality as well). However both the 3DS and the Wii U has no big IP, at least yet. Will we ever see big new IPs from these systems? If we look at the games I listed above, we can see that all of the franchises have had recent/upcoming entries, possibly with the exeption of Nintendogs. I have wondered if Nintendo could make X into their big new IP for the Wii U, a Final Fantasy rival of sorts, to try to bring the Japanese console market back to daddy. I honestly think they could do it, although I do not see them pulling it of unless they change their marketing efforts, and start pushing the game more. 

Could we possibly see a big new western IP for the Wii U? A shooter, WRPG, MMO or Adventure game from Retro maybe? Or will Nintendo actually pull their finger out of their ass and get some more western first party devs? I'm mostly tapping into Wii U here, since I do not see any big 3DS title incoming (Monoliths 3DS game could do well though but not close to the games listed previously), but feel free to bring 3DS into this as well!

So will we get a big new IP for the Wii U or the 3DS, what genre and which Nintendo developer will be behind it? Or will it possibly be a Nintendo funded game made by a second party? 

Miyamoto's secret new IP project?

WiiU, maybe since Nintendo is probably desperate to try anything to make that a success... A 3ds is less likely from Nintendo imo since they can play it safe and it will still sell...

On the other hand, it could be the opposite since if the new ip fails on the wiiU, it will hurt them more than if it fails on the 3ds but I think there might be something new on the wiiU

This is what I was thinking!

He still has to announce what kind of project he is working on. Who knows maybe it's a mindblowing IP that will sell millions!

Will it be a big one though? He has stated that he himself have tried to shift towards smaller games. We might just get a new Monty Mole. Hardly big, both in scope and (unless they publish it on phones) sales. 

Based on the way you organized the OP, how should we know? What if Nintendo Land 2 sells 10 million on a future console?

It's aprediction, like 90% of everything else that happends on this site. We don't know if it'll sell 10 million in the future, do you think so?