The RTM of windows 7 has been out for 2 months now? 3 by the street date of Oct 22nd.
This time is of course used for manufacturing, marketing, etc.
Meanwhile they should be offering fully updated ISOs directly on the windows site for everyone and anyone to download - the OS itself contains its own validation so there's no harm in letting anyone download it. Then you buy your key digitally with a steam-like system, this would even benefit Microsoft by serving as a key registration system.