It should be just as possible to build the nvidia drivers with just the header files if they're setup properly. The last time I checked the only hurdle was the that wrapper script was a bit simplistic about what it looked for, and fixing that was on the list.

For the last time, there is no plan for a DVD release. There is no plan for a 2 CD installation set. In the next release, those that want the kernel source can run a script that will get it. The headers in the next release is a more complete.