I'm not really sold on the idea of Disqus from what I've heard. From what I've read it's a product that allows you to (if you are a publisher) install it on your "article" page and it will track comments and provide an external forum (wtf?) I think it also has some sort of global login dealy so that if a lot of blogs in your bookmark list use it you can use 1 login and it will track your history and "rep".

I think the market is too small here, but I do think the idea is fairly solid and along the same lines as Open ID.