A student at the Kennedy School of Government at Havard released this paper/survey about the behaviors of collaborative media consumers. From the site:

Why are collaborative news, commenting and blogging sites such as Newsvine, Slashdot and Global Voices attracting users and visitors? Who are these folks? What do they want from their interactions?

Link to the page at the Center for Citizen Media and to the 60+ page .pdf of the report.