I would imagine that even if you wanted to enter the store just to play with the demo, you would need to wait in line. It's possible that they'll only be letting people in 10 at a time (or some number). There was a rumor about 50 at a time for Apple Stores. I imagine AT&T would be less. Other than waiting in line with the rest of us, I don't see any reason why you couldn't come in and play with the phone and not buy it.