"So much for "free" as the future of business - as far as Ning goes, anyway. The company accepted hundreds of millions of dollars from investors, and they apparently want more of a return than Ning is able to provide as a free service."
One alternative for free class site / social network now that Ning is going all premium.
"Spruz allows you to create a free social website to attract others with similar interests, strengthen customer relationships with your business or rally behind a cause. Spruz was officially launched March 2007 by its founders Jay Roberts and David Furman. Spruz is self funded, developed and managed by its founders. "