This has actually gone public, without any request not to say anything, so I trust it's OK to mention it to anyone who finds themselves here and doesn't know yet. I know I'd want to know! :-)

Eliezer has completed the first draft of his rationality book based on his two-year sequence of blog posting on Less Wrong, packed with hundreds of pages of novel content.

The manuscript is over 280,000 words long (over 500 pages) and has been split into two sub-books. The next steps are thoroughly editing the text and moving towards publication.

Yay! :)