Teachers and students are embracing web technologies such as blogging and podcasting. Although not designed specifically for use in education, these tools are helping to make e-learning far more personal, social, and flexible.
Couple that with the trends in "Sustainability" and you have Sustainable Social Networks for a Greener Web 2.0.
One of the leaders in social networks for education is an excellent example of how web 2.0 is shaping e-learning. Elgg is social networking software designed especially for education - built from the ground up to support learning.