I'm actually more optimistic about what "Big Society" can potentially achieve than most people I know, but I recognise that actually, most of what it can achieve is (significant) optimisation of already-funded and already-managed programs that are set up with the correct social tools. Which is why I found this such interesting ready: Charlie Stross, in the course of wondering about how many people you'd need to send to Mars, ably demonstrates why society is already far too large and complex for "Big Society" to ever work past a certain limit.