Interesting.

For the books I'm working on (http://justthebestparts.com) I went with CommentPress to allow per-paragraph comments.

I also wrote some local tools so that I could write locally using vim + markdown, then export to HTML and upload that into the remote WP instance.

Thanks for sharing that about CommentPress, what a great project.

It is really sweet. Just be sure to activate Akismet to help contain the comment spam. :)