Steve Kelman has Knowledge management 2.0 in the July 14, 2008 Federal Computer Week magazine. It's a short article, but the gist seems to be this paragraph from the middle.
If yesterday’s catchphrase was knowledge management, today’s is collaboration. To some extent, knowledge management and collaboration have common features. However, knowledge management has a more vertical, hierarchical sound, implying wisdom gathered by headquarters employees who then pass it to the field. In contrast, collaboration has a more horizontal, peer-to-peer sound, more of a wisdom-of-crowds feel than one of central direction. Of course, a central office, at least in CBP’s case, has established the infrastructure for peer-to-peer collaboration, and it might be sensible to codify ideas that emerge from collaboration.
It's all about collaboration. Kelman is reporting on several efforts at Federal agencies related to enabling people to collaborate. When applying the "2.0" moniker to knowledge management (or the enterprise), connecting people is frequently the biggest element of the discussion. And this connection usually gets turned into enabling collaboration. I've done it myself.
Interestingly, I found this from an intense discussion at the actKM Forum discussion list. The gist of the discussion is that, while collaboration is important, knowledge management has a much wider impact than strictly collaboration. As usual for actKM, the discussion ranged well outside the tight confines of the original topic.