There are rumors going around that Nintendo is working on the Wii's successor. Sporting HD capabilities and "built-in" HD video screen as well as graphics that will surpass the PlayStation 3 and Xbox 360.
Publishers are already planning launch titles and the new controller will be tablet of sorts. An iPad with buttons. Of course this is all just speculation and Nintendo is denying any of these statements but expect the formal announcement to be made before or during this year's E3 ( Electronic Entertainment Expo).
Maybe this is the reason why there seems to be no other major Wii game announcement outside of The Legend of Zelda: Skyward Sword. It's no surprise to me that Nintendo is working on a new platform, what worries me though is that graphical horsepower that rumors claim to be more powerful than the PS3 and 360 are obviously going happen, but maybe it'll be significantly weaker than whatever it is Sony and/or Microsoft will pull out in the future.
Nintendo has surprised us time and time again and for most part of gaming evolution has flagshipped many innovations of how we play video games either in our homes, on the bus, out in the park, or even on the can. I'm sure that they are gonna wow us again.