There is much to say about it but I'm only making one observation today.
Commenting can be a great way to open up 2, 3 and 4 way communication between the content providers and the content receivers. It can be a valuable tool for the creation of movements and the exchange of new ideas. But we all know that that isn't always the case. These days anyone can join the "conversation" and for many reasons this conversation can degraded.
The quality of the comments not the quantity creates the value, that's why I like what CNN is doing. Instead of open commenting on the articles, they are aggregating instances that the article has been blogged about.
What this does is create a barrier of entry to the conversation. You need to care enough to read the article, go to your blog, write about it and publish to your own community, in your own name. I imagine this raises the level of value in the "conversation" surrounding articles. Although it doesn't fill the same self-help function some other sites provide though*. You think?
*no disrespect to the old HP. I'm a good Huffington Post loving liberal.