1. They probably have a huge backorder from the $250 price advertised here at Hot Deals (and no doubt at other deal fora). So they may have committed their production until then to satisfy existing orders.
2. I'm not sure if other ATI card sellers appreciate ATI competing with them in the online space, so ATI may not want to keep an unlimited supply of cards at their store. OTOH, I'd think they'd want to keep more than zero on hand.
So I can understand their being sold out at their online store, tho the otherwise unavailability of the XL at MSRP this long after launch is pretty lame. For shaaaame! </Abe Simpson>