I dunno, Google seems to have beaten them to the punch and no matter their culture, I'd still call them a traditionally hierarchically structured organization
The fact that people sit down and make time to come up with initiatives like this is something I truly admire, no matter how big their audience or the volume of their network.
They have a couple more page views than the YC alumni network.
They do. I for one, wish they'd stop doing it for FF users too though. It's getting really annoying.