Mark's book finally went on sale yesterday. You can get it from Amazon. Obviously.
It's called Herd: How to change mass behaviour by harnessing our true nature.
Mark's written a rather touching post about the launch over on Herd, where he talks about Ubuntu. [You'll have to go read it if you want to know what that means.]
I'll let you know what I think once I've read it but having spoken to Mark, seen him present ideas from the book and read the groundbreaking paper it has grown from, it's certain to be good.
As Russell points out in his foreword, its got some big theories that may require you to completely rethink how we think how stuff works but it also has pictures and jokes, which sounds very promising.