I found an intriguing product PrinceXML for creating PDFs from HTML documentation. XML.com has an article Printing XML why CSS is better than XSL. This product is being used to typeset a new edition of the book Cascading Stylesheets, designing for the web by Håkon Lie and Bert Bos.

I will have to play with the demo and see how well it works. Note to self, compare it against CSS2XSLFO.