The idea here is to associate a chat room with each blog post. So instead of having people submit comments, they would participate in a real-time discussion associated with a particular blog post.
It is important to have a "chat schedule" for each blog post. For example, you might announce 3 chat sessions, each 20 minutes long, for a particular blog post. This sort of schedule is important because you would like to have a reasonable number of people available for real-time chatting.