if you look closely at the iPhone in the background, u can see what looks like two circles. possibly a sensor or a camera. it's kind of hard to see. Pic #1 - Original, Pic #2 - Brightened.
And what about on the second phone in your shot - another circle that matches the one seen on the one demoing MobileMe. There's definitely something there - either there is a circular mark on the case, it's a reflection of a light or there's something on the front of the phone. You can't tell which, but it would be strange for a reflection to appear in the same place on all the phones and not anywhere else on the glass front. I guess we'll see on the 11th....