Hi.
The actual DDK can be obtained through MSDN-Subscription or ordered on CD (shipping and handling fee), as you can read here:
http://www.microsoft.com/whdc/devtools/ddk/default.mspx
They forgot to mention, that the KMDF-ISO-Image (~300MB) has a subdirectory with the name "w2k3ddk".
Kernel Mode Driver Framework: http://www.microsoft.com/whdc/driver/wdf/KMDF.mspx
Do not forget to read the License. (.... to design, develop and test your programs for use with Microsoft Windows software)
So IMHO, wine is really a set of API-Testing Programs with some Examples (in programs). The other Code is only an addon to make our API-Testing Programs and Examples work on unix ;-)