Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
The paper receipt I got at preorder and the email I received from AT&T said the phone would be activated 7 days after shipment if not activated by before then. My local store rep had not heard of this though (if that means anything). Not sure what really will happen. I'm assuming most people activate right away anyway. But let us know if you decide to wait.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.