More Enterprise 2.0 bad news: Ning is down

Just yesterday, I described poor reliability as a key weakness in the Enterprise 2.0 model. Today, as if on cue, Ning, a social networking startup founded by Marc Andreessen, is offline:

Call me old-fashioned, but I prefer reliability, consistency, and high availability in my mission critical software. It's bad enough when a consumer site such as Netflix goes down; it's far worse when a business platform such as Salesforce.com goes offline.

Is Enterprise 2.0 actually ready for prime-time?