Oleg Tkachenko writes

The goals of exposing comments are: enabling for arbitrary RSS reader application to see comments made to blog items and to post new comments. There are several facilities developed by RSS commutity, which allow to achieve these goals:

  1. <slash:comments> RSS 2.0 extension element, which merely contains number of comments made to the specified blog item.
  2. RSS 2.0 <comments> element, which provides URI of the page where comments can be viewed and added (it's usually something like http://yourblog/cgi-bin/mt-comments.cgi?entry_id=blog-item-id in MT blogs).
  3. <wfw:commentRss> RSS 2.0 extension element, which provides URI of comment feeds per blog item (to put it another way - returns comments made to specified blog item as RSS feed).
  4. <wfw:comment> RSS 2.0 extension element, which provides URI for posting comments via CommentAPI.

It works like a charm. Now users of SharpReader and RSS Bandit can view the comments to posts in Oleg's MovableType blog directly in their aggregator. Posting comments from RSS Bandit works as well. Hopefully, this will catch on and folks no longer have to choose between .TEXT and  dasBlog (i.e. ASP.NET/Windows based blogging tools) when they want a blog tool that supports exposing comment in their RSS feed. The more the merrier.