The CLHS[1] they mentioned has been available online for ages. What they're talking about is making a more modern site. Generating a PDF from the spec wouldn't get them any closer to that goal.
Then don't put a specification link on the home page and wait until it is done. The text is non-helpful to marketing the language particularly when books are actually available and linkable that can be read now.
[1]: http://www.lispworks.com/documentation/HyperSpec/Front/index...