Having just seen the speech of Iwata I'm partly excited but still a bit unsure about it. I still have to see some real games being played with the controller or maybe trying it myself to get a better look of how it works.
I think you can do a lot of cool things with this controller for example in Zelda where you can control the exact movement your sword makes or when shooting an arrow you have to use the controller to pull it back aim and let it go. Or you can select things in the menu by pointing and clicking.
But I don't know how it will have to be used in other games like for example Fifa (I personally never play this, but for people who do) how do you shoot the ball. I'd think it'd feel weird using your arm for that.
Also your arm will get tired after a while from too much waving around which can possibly be a problem I think if you want to continue playing. Maybe there's still a way to play without the need to point at the TV.
I hope we'll get some more info soon especially some demo videos.