A large number of educational communities have been created in Ning generally using a free account. From July these are now going to cost depending your plan. There are three plans: Ning mini, Ning Plus and Ning Pro. The cheapest is Ning Mini at @2.95 a month. They say that Ning Mini Networks will be available for K-12 educators and their students that a 'major educational company' is sponsoring this. Higher education appears excluded from Ning's educational plan.
I have been reading Steve Hargadon's blog about this as well as the information on Ning. Steve's blog is a balanced account of the changes.