AT&T has confirmed that its website has sold out of its launch day stock of iPhone 4 units. In a statement released to Engadget, the company said, “Because of the incredible interest in iPhone 4, today was the busiest online sales day in AT&T history. As of Tuesday afternoon, customers who preorder iPhone 4 moving forward will receive their device on June 25 or later, depending on when the order is placed. We’ll email customers…
