I see some of the great benefits of (the now old) Moxie's Convergence or CM's Perspective. However, how do they fight the attack of a MITM sat in a common network path of both client and notary on the way to the server? Both the notary and the client will see the same forged certificate, and it will be validated as correct.
Yes, different notaries are in different locations, but what if all of them have to pass through some common network path? (e.g. the Great Wall of China)