I've been really impressed by the ning interface (and this network of course). I had a look round some other ning communities today (wow, there are many!) but few as active as this one.
One of the really appealing things about a ning community is the web interface. It integrates so many crucial aspects so sweetly - blogs, forums, video, audio, images.
The 'my page' is a neat feature that I've not seen in Moodle (our institution's VLE) and I wondered how I could integrate a ning community with Moodle. The 'my page' certainly fosters ownership of each individual's contribution to the community. I notice that if you create a ning community it can remain private. You could move (link) learners into moodle where a ning community runs out of features (though I'm not sure where that is yet!).