The Truth of the Matter is this.
The Wii just isn't as interesting as the PS3 or 360, not to mention the Motion Controls aren't exactly what people want either.
I'm not saying they're bad, Zelda's Motion Controls are actually pretty well done and it's pretty impressive, but I talk to people about Games on the Wii and they're just like "It's not for me." or something like that. It's that "Nintendo is for Kids" Mentality.
What Nintendo needs to do is to cut that Myth into pieces, which means opening up more space for the File Size of Downloadable games (which it seems like what they're doing for WiiU and 3DS), Make games with a more Traditional Controller Layout (Classic Controller and WiiU Controller) and get games that these gamers want to play, like Assassin's Creed, Dead Space, Red Dead Redemption, etc....Not to mention they need to up things to an HD Resolution because apparently we have a lot of Graphic Crazies Out there now that think Resolution is end all be all.
Another thing that I think is what went wrong with Zelda Skyward Sword is the Linearity of the Game. They should have made the game a bit more open.