OpenStudy : a Big Idea or just another Q&A system ?

I Recently read a blog entry at CACM: Our Big Idea: Open Social Learning .  The article mentions a project which is a a start-up company spun off by Georgia Tech and Emory University. Its Web site is the latest effort to create a social platform for independent learners who want to help each other study the huge trove of educational materials published free online by universities like MIT. Another way to describe this Project is as a Open Social Learning aka Massively Multiplayer Online Learning

The Idea sounds Great But is it really innovative? .  as it stands now , openStudy is merely another Q&A website . There exists new modern Q&A systems like the popular Stack Exchange web sites network which is

a fast-growing network of 51 question and answer sites on diverse topics from software programming to cooking to photography and gaming.

many students , researchers and scientists use now extensively the Stack Exchange network sites to conduct open study collaboration on various scientific topics like mathematics , physics , programming and many other STEM topics.

In your opinion what makes OpenStudy really a Big Idea as their founders describe it? will it really take its promise to revolutionize the STEM learning process in the world and become the Facebook of schools? what is your evaluation of the OpenStudy project ?