iPhone 4 pre-orders have already begun shipping to some eager customers from warehouses in China. Reports are pouring in from some people that have already received email notifications from Apple that their iPhone 4 pre-orders have shipped and will arrive on time this week. While the official launch date is June 24, some of the notifications have listed the delivery date as June 23, a full day ahead of schedule. Don’t get too excited though, as it’s likely that most shipping companies will hold the packages to make sure no one receives their new iPhone before June 24. However, with the launch of the iPad, some customers did end up receiving their package a day or two earlier than expected.

Over 600,000 pre-orders were submitted in one day, causing Apple and AT&T webservers to crash. Line-ups will probably be long for those who didn’t manage to get their iPhone 4 pre-order shipping notification. Currently, the list of retailers that will be selling the new iPhone on launch day includes Radio Shack, Best Buy, WalMart, AT&T and Apple. It’s possible iPhone 4 launch day lines could be separated into pre-orders, pre-authorized orders and new customers, further complicating the process in a time when customers are already frustrated over the short supply.