I could easily be wrong — but I think the trend is that people are moving away from comments that appear with articles on websites, since the comments are usually not that interesting.
They’re at best not interesting; often they’re bad enough to make you wonder if we wouldn’t be better off with parakeets or wolves as the dominant thinking (or “thinking”) species rather than us monkeys.
Instead people are following other people on FriendFeed, Facebook, Twitter, delicious, etc. -- they get to hear what people they think are interesting say, instead of what just anybody says.
It's not the same thing, but it is the same thing in the sense that it's listening to other people's voices.
My thinking is that there's a certain amount of attention for that, and things like delicious take attention away from on-site comments.
I'd rather hear what any of my friends says on any topic, rather than what people I don't know say about a specific article. And I think that’s more and more true for more people, now that we’ve all seen what on-site comments are like, and how they’re getting worse.
(Not all comments everywhere are awful, of course. And my theory could just be me projecting my own thoughts on the web-at-large.)