Collaborative learning solution/platform for an industry association?

Can anyone recommend software solutions to consider for facilitating collaborative learning within an industry association online? For example, Scoop kinda gets at this as a blog publishing framework: http://scoop.kuro5hin.org/ but I’m looking for something a little more full-fledged. Ideally our members would be able to take ownership of running SIGs, posting articles, facilitating/promoting live-webcast/chat presentations, etc.