Ok, let's analyze the situation for a bit. When the Wii came out, it had lot of selling points:
-Virtual Console.
-Retro Compatibility with Gamecube (a console that didn't sell very well outside of core Nintendo fans).
-A very different controller that promised a different expirience.
-A game included (Wii Sports).
-It released with a Twilight Princess.
Now, looking at the WiiU, it doesn't have those. Please, see that I'm not bashing the WiiU, just saying that other than better 3rd party support (which is also available on other consoles for the most part) it still has to get a few selling points. I don't know if the WiiU will be successful, but it'll definitely take a while for it to take off in sales.
I think Nintendo will focus their marketing resources on giving Skyward Sword and the Wii one last marketing push before giving it the eventual good-bye kiss. At least for now. I mean, the only real first party support shown at E3 was the tech demo, and that doesn't count as it's not even a real game.
Not to mention that the Wii has a huge install base already, as already mentioned, which will make it more logical to push Skyward Sword. I think this could be a God of War II kind of situation. There is hype for the new console, but the already established userbase is where the marketing will go. The development resources will be focused on making games for the next console while they try to get some more sales out of the old one.
Also, I haven't seen another game that tried to implement motion control in a more core-oriented adventure game. The closest I've seen to Skyward Sword is that Kinect Star Wars game, and it definitely won't be as complex.