I have enabled Disqus comments for posts on this blog; I've already received a few (not many, of course) emails regarding posts, maybe this will help such conversations stick closer to the blog posts if there's material of relevance to others.
On the one hand, I think the social web has greatly improved the potential for positive feedback within communities increasing the amount of signal available. (Alas, the noise is also increased!) On the other hand, I am not entirely comfortable with the linking of accounts and tying together of fairly large amounts of information across multiple domains and topics. Disqus, being a third-party comment service, does serve to link users who might interact with this blog with external services that mine that information. I have allowed anonymous (guest, in Disqus terms) commenting with moderation, to help combat this for those who want to minimize the breadcrumbs.
I get far more feedback on the technical articles on this site. If this trial goes well, perhaps I'll use Disqus to add comments to those articles (or at least the most popular ones). I find it more likely that every article will have a depressing “0 Comments” link at the bottom, and an empty Disqus entry begging for first posts.