It seems to me that Nintendo is trying to find new interfaces because they can't come up with any more innovative gameplay.
I'd take innovations WITHIN THE GAME (IE SOFTWARE) over gimmicky games that are made based around an "innovative" interface any day.
Look at games like Portal, THOSE are proper innovations, they use the interface they have, and use it only as a means of controlling the game. It serves it's purpose, but they didn't come up for the idea of Portal as a way to use some new controller. It's important that the interface have the least influence on the game as possible, it is a middle man between the player and the game, and as someone plays a game they should not be thinking about it. (For example, in an fps they should be thinking: "I need to shoot that guy" then shoot him, not "I need to wave my wiimote (or tilt my DS) in a half circle in order to shoot that guy". If they have to think about how they need to use the interface as they do it, that is a failure of the interface, it should be automatic)
Case and point, the interface caters to the game, the game should NOT be designed from the ground up as a way to use the interface. Could you imagine if movie scripts were written completely based on new ways to take advantage of a new projector?
This seems to be a big movement toward bridging the gaps between games and real life: "Want to swing your sword? Swing your wiimote like a sword!" "Want to look left? Turn your head to the left and the DS will change the perspective!" I don't play games in order to feel like I'm doing something in my own life, I play them as an ESCAPIST (see what I did there? You saw what I did there)
All those for innovative software over innovative interface (which is just a middle man) say "I"!