I'm using the Disqus plugin, and I like it a lot. One thing that would be cool, however, is if the login on the plugin (for purposes of commenting) could somehow include the clickpass widget. That would really make it easier to encourage commenting, as people would see that they have many options. Some new users who don't already have a Disqus account don't realize that at the site, they could create one with, say, their Yahoo or Gmail account, and never have to create yet another password.
If we could make that more obvious on the commenting plugin itself, I think it'd be a definite win.