Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
The only reason the DSi needs a camera to do that is because it doesn't have an accelerometer. The iPhone or iPad can do that already.
 
They have something like that with the accelerometer (the hologram thingie).

But it would be interesting using the camera instead of the accelerometer.
 
This is different than using the accelerometer, the camera can tell from where you are looking at the screen and alter the image to appear accordingly rather than just the angle at which it is being held. VERY cool IMO
 
T the camera can tell from where you are looking at the screen

I would be surprised if this is what it actually does. My guess is that it just tracks the motion of whatever happens to be in front of the camera (whether its your head or a cheeseburger) and uses that to adjust the view. You are right that it's not the same as the accelerometer though, because the device can stay still and you can move to adjust the view.
 
I'm doubtful it does eye tracking, as others note. It's just looking for movement of whatever the biggest blob is in front of the cam. The iPad could do something similar with accelerometers, but not the same.

Think about it like this: the DSi with head tracking simulates looking out a window - as you peer around it changes what you can see. The iPad would simulate a diorama - you can tilt it around and see different angles on the scene without moving your head or eyes.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.