It wont be a launch game.
That's a guess you're stating as fact, isn't it? Pikmin 3 is probably already done and could be shipped today. If it's between Pikmin and NSMB for which one shows up first day, I'd say Pikmin. But that's just me. My predictions: Nov 18th launch.
My guess is that Nintendo will launch with Wii Fit U and NintendoLand (which will be bundled). Pikmin 3 will be there too, as their core audience game. That franchise is loved, but many overlook it, so it needs the launch attention.
They'll make NSMB U their big December title to continue momentum, ala Melee for GC and Kart 7 for 3DS. This way people will have a chance to buy Rayman, as showing that 3rd parties can get sales needs to be #1 on Nintendo's to-do list. They certainly don't need 2 quality 2D platformers competing, and Rayman would get ignored. So at least give that game a few weeks to shine. And Zombi U will give them a "mature" / FPS option that will hopefully show some strong 3rd party sales as well.
We'll see P-100 during the Jan-Apr software drought, since it's a new IP and will also need the attention of being the only thing of note being released in that window. Maybe Wario Ware then too. That game just doesn't seem fleshed out enough to me to seem ready. Unless that's potentially an e-shop only release. That one would just end up getting ignored in favor of NintendoLand anyway if it launched.
One scene of Panorama View will be in the software as a tech demo like FaceRaiders, with options to download more at the e-store.
E-store will launch with Luigi's Mansion for GameCube and probably little else. A nice tie in for the 3DS version, at least. Jan-Apr will see a GameCube e-store push to combat the software drought. Maybe even a Wii classic game or two will crop up.
I also expect a Wii Sports U announcement soon, maybe at a Nintendo Direct for an early 2013 release. Wii Motion Plus version of tennis, an HD version of bowling, along with the already shown Golf and Baseball.
E3 2013 we'll finally see some bigger budget games that are certainly in development but were too early to show. Retro's project will probably be Kart U, since they worked on the 3DS version. Or Donkey Kong Returns 2 - but again, there's already enough 2D love IMO. Maybe DKR would be a 3DS title?