OK, it is cool. Using the compass, GPS and accelerometers to tell how you are holding the iPad at the sky for the planetarium app is just awesome.
One thing they need (apart from a camera) is a cunning way to measure blood alcohol. Something that tests the sweat on your finger tips on the touch screen or something. Then you could have it automatically tag blog posts with BA level so people can tell how seriously to take them. Maybe something that won't let you post above a certain level and you have to approve when sober.
Would be a killer app IMHO :-)