

Despite receiving notifications from Apple earlier this week that their iPhone 4 pre-orders would be arriving today, one day ahead of the official launch, a number of U.S. customers have noticed that the tracking information for their shipments through FedEx are suggesting that they may not be receiving their orders today.
Those customers can still hold out hope, however, as FedEx has posted a service update reporting that deliveries are proceeding as scheduled but that updates to tracking information are being delayed.
While the notice does not specifically address iPhone 4, it seems reasonable to assume that the volume of shipments going out today is causing some issues with FedEx's tracking system.Package deliveries are proceeding as normal, however tracking updates are temporarily being delayed. Please try back later.
A few customers were even lucky enough to receive their shipments yesterday, with many more already being delivered today.

Apple Store, Regent Street
Meanwhile, customers looking to score iPhone 4s at their local Apple Stores tomorrow are beginning to form lines at locations around the country.

Apple Store, San Francisco
Article Link: FedEx Issues Service Update Noting Delayed Shipment Tracking Information