Supply of white iPhone 4s looking low for launch day

The unauthenticated memo was published by modmyi, the same outlet which leaked an accurate memo last week regarding the carrier's intent to offer a iPhone 4 trade-up program for recent iPhone 3GS buyers.

According to the latest memo, AT&T stores will only take reservations for the 16GB and 32GB black iPhone 4 starting tomorrow, and won't have white models to sell until sometime "later this summer."

None of Apple's other iPhone U.S. resellers have issued word of such restrictions and it's therefore unclear if the availability issue is specific to AT&T or a hint at a bigger problem that may become public when Apple officially kicks off the pre-order process tomorrow.

However, it's also being reported that both Soft Bank of Japan and Deutsche Telecom won't have white iPhones on launch day either, suggesting a broader issue may be materializing.