You need to go to:
http://www.codeplex.com/cssfriendly/...ReleaseId=2159
- which is where the project has landed.
However, things are not as they are described in the book. You don't get a .VSI, you get the project files in a ZIP. This only contains the CSS files for the Menu, TreeView and the DetailsView. I don't know, I think this project is dead. It seems there aren't that much interest in this topic. I mean, look at this forum, 12 posts since the beginning, and this book is still the only one on this specific topic.
I really don't understand why Microsoft didn't re-write the controls for .NET 3.5 ala the ListView control, in which you have full control over the rendered code, right out of the box...