The entire Shader X2 book and source code has now been released and can be downloaded for free! Hot off the press, get it while you can! It is still a worthwhile resource, even if it is DX9-era (2004) technology.
If your in the process of looking for good graphics,games, and physics simulation related books, the Mr. Elusive website has a great list with some fantastic books, and also a few duds.