O2 UK announced today that it will only offer the iPhone 4 to current customers when the handset launches on June 24th. The wireless carrier cites extremely limited stock as the basis for this potentially controversial decision. Folks looking to score an iPhone by signing up now with O2 are out of luck as the iPhone will only be offered to wireless, home broadband, and home phone customers who have been with O2 since May 24th, 2010. Current customers will have to travel to a brick and mortar store to snag an iPhone as the incredibly hot handset will not be available online from O2 until the end of July. Once the supply of iPhones is no longer limited, O2 will finally make the handset available to new customers.