I just installed the Disqus commenting system. Let me know what you think of it and if there are any glitches.
Update: 9:30 PM. Disqus is still processing the comments it exported from here. It says it can take up to 24 hours for everything to be done with all the community features working. For example, I see a very recent comment from Ten Bears in the WordPress comments that doesn’t appear in the post yet. Disqus is probably still processing this comment, and others.