iPhone 4s ship; customers hope (in vain) for early arrival
Apple always has the shipper hold the delivery until the exact day of launch, in this case, June 24th. No matter what your tracking info says, the device will be held, at the request of Apple, and customers will see their tracking info updated in that way later.
If in fact FedEx were to delivery these early, someone would be in big trouble.
That is, of course, assuming that your order hasn't been canceled. Reports have appeared stating that Apple and AT&T have been canceling orders randomly.