Refining the Idea of Student-Generated Content

A couple of things happened recently which made me realize that I need to refine my concept of student-generated content a little bit more. One was a conversation with a colleague during which I expressed an interest in SGC, and the response was that it's all over the place, especially in the form of Web 2.0 apps such as YouTube, Facebook, etc. and that it's old news. Both of these observations are true in a way, but I'm trying to get at a way in which they're not true. More specifically, I'm looking for applications of SGC in formal education, not formal education -- where SGC is integrated into course assignments, assessments, and (even) the syllabus itself. Examples of SGC in informal education abound, but it is still very restricted. There is also much less conflict about its use in informal education. So I'm also interested in exploring more about the adoption process itself, i.e., what stops teachers from allowing students to generate content, or what empowers them to do so.