In the past, the Windows DDK has been available for download from: http://www.microsoft.com/ddk
When XP is released, the latest Windows DDK will *not* be available for downloading from the web. This is, at least in part, because the new DDK contains a full set of development tools.
So, what do you do if you need the final DDK FAST, like you want to get your driver ready for the official customer release of XP, and you're not on the XP Beta program? Simple: Place a PRE-ORDER for the ‘XP DDK on CD’ via the Microsoft web site! The DDK is free; you just pay shipping and handling charges. This way, as soon as the XP DDK is ready, Microsoft will fire-off your DDK CD.