This blew my mind.
There was also this new labyrinth game on the iphone/itouch that used to accelerometers to change the perspective of the walls. And let's not forget that one Wii prototype where the game would move according to where you were standing.
I love these kind of effects, they should definitely be used more often in these types of casual games to make them more entertaining. Of course in an actual hardcore game, it would get annoying, but here it works perfectly.
EDIT: Now that I think of it, it's probably the only thing the DS lacks (Accelerometer).
It has pretty much all the tools needed for homebrew potential (microphone, wifi, touchscreen, etc) but yea it could definitely be that much better if it also had an accelerometer.