AT&T has completely sold through its launch day supply of pre-order iPhone 3G S units, according to a new report. Citing an internal AT&T memo, Boy Genius Report claims that only pre-orders placed prior to Saturday, June 13 are expected to arrive at stores in time for a Friday morning pick-up, while customers placing pre-orders after that time should be told their order will arrive between 7-14 days from the order date. It is currently unclear…