BestBuy is now showing MacBook Air’s as unavailable as Apple is likely moving remaining stock to its own retail outlets in anticipation of a product refresh that has long been rumored.  Likely the Air will release with Lion or very close to it.  Expect the new MacBook Air to feature improvements such as Thunderbolt, 6G SATA, and possibly a 6G Capable SSD Drive either as the high-end, or as a BTO option.  It should also sport the latest Intel processors such as low voltage i3, or i5 processors.  Less likely is a 15″ version as that may be too bulky to be considered Air.