For me the difference between a discussion group and a team blog is the feeling that we are all here for the same thing. That's not always the case with discussion groups. We have a community here and that means that certain conversational niceties have to be observed - keeping quiet while others have their say, smiling, nodding encouraging, or shaking our heads. What it isn't is a public meeting where people shout at the podium or each other.
As far as the Jenkins article is concerned, he hits on the essence of communication using the web. If you cast your bread on the waters,then it will come back to you. It may be wet, mouldy and unpalatable when it arrives, though. Traditional journalists have spent most of their lives saying that they understand their readers without really doing anything to get to know them better. When the readers have turned up and given their opinions, there is a tendency for journalists to suddenly rely on their position in the "establishment" and stick their tongues out and waggle their bottoms with a "I know best, so there" attitude.
That's not good enough any more. People can and will answer back. The challenge is going to be to come with a measured and valuable response to the hail of criticism that might result from an article.
PS please don't take me of the list because I have been so bad at posting Jeneane, my silence has been an eloquent comment on things. (honest)