I have been trying to access the Classroom 2.0 website from Shanghai without success. I keep getting a Page Load Error. However, using NinjaCloak I can access it but probably with drastically reduced functionality (as happens with Facebook). I guess it's only to be expected given the Government's current paranoia but it's a sad state of affairs.
All ning sites were blocked last November and have since been unaccessible unless using a proxy server. This is part of the governments crackdown on most English language social networks and with facebook, twitter and others joining around the time of the Tibet anniversary. We were using ning successfully with many groups of students at my school in Beijing but had to find other ways to do this when ning was blocked.