In a moment of pure meta, I'm posting here on Classroom 2.0 while we talk about Classroom 2.0 in an session at the edubloggercon about virtual learning communities.
So... I'd argue that Classroom 2.0 is more of a VLC than someone's blog. VLCs bring with it some very different values and therefore brings different people (with a great deal of overlap, obviously) to take part in the community.
What do you think brings people to something like Ning as opposed to (addition to?) the traditional blogosphere?