They were moving it from FreeBSD to Windows, just like Hotmail did after Microsoft bought them all those years ago. Not sure which platform it's running on at the moment.
John if that is true – i.e. moving Ning from a UNIX-class operating system to DOS-Windows – it is surely an act of folly. You'd have thought the poxy-DOS-box operation (AKA M$ AKA The Beast of Redmond) might have learnt from that Hotmail debacle. Netcraft yields inconclusive data unless you know what "F5 Big-IP" is ...
I can assure you Matt it was global, but not universal - the Ning status blog eked out bits of the worldwide chaos, but by no means the whole truth and nothing but: