Can you propose an alternative? I'm considering converting my blog to a static site with Octopress/Jekyll and need a commenting mechanism. I dislike Disqus as a user, but I know of no self-hosted alternative.
What's wrong with Disqus?
One disadvantage is since the comments are inserted with Javascript, certain robots have a hard time parsing them.
Other disadvantages:
You're handing over control of your user base to a third party.
Some people don't like Disqus tracking them all over the web.