What happens is that in the store there is a "special" version of iTunes that is used to activate. To activate it seems they are downloading it, then connecting to the server to activate.
The problem is EVERYONE that is buying one and EVERY store that is selling the phones are doing it basically at the same time, so there is no ability to activate.
I got mine early and then went back with a friend. In Albany, NY they are basically sending people out the door with a phone that does not work and telling them to come back in a "couple days".
This seems to be most problematic for people trying to transfer a number for some reason.