roberthking:Perhaps I'm missing something, but why would you want to compile the CSS into the assembly? Doesn't that preclude making presentation changes without requiring a recompile?
The CSS compiled in the assembly are the base rules that provide functional presentation details and can easily be overridden by your own CSS markup. There are only three possible CSS files -- for the DetailsView, Menu, and TreeView -- and each are very limited in what they actually do (take a look at the source code in the distribution to see exactly what is done).
The compiled assembly makes it easier to utilize the CSSFriendly adapter kit as a framework without having to include the source code and related files. The CSS files themselves could be removed from the distribution if you don't want them, too.