However, TACK only protects you after you've visited a site for the first time. If a person is targeted by any organization that can sign a fraudulent certificate before the first time they visit a site, then they are still vulnerable to MITM. Given that many countries have root CAs, many governments have this capability.
Namecoin does not suffer from that issue.
Namecoin and TACK solve different problems. One is an incremental improvement with backward capability; the other is a clean break that attempts to provide stronger guarantees.
"you are vanishingly unlikely to do a better job of designing an encrypted channel than every cryptographer and protocol designer and software security person who has poured time into TLS"
It pains me to see this kind of arrogant dismissal as the top comment so often.
The author said nothing about designing his own protocol. He simply explained the problems with the CA system and the way Namecoin (specifically the DotBIT proposal) might solve those problems. This would simply add new functionality: supporting .bit URLS where the clients looks up the certificate through the blockchain, without trusting the CAs. After that first step, the encrypted channel implementation can be the same. And the blockchain concept (and even Namecoin's specific implementation) is shared with Bitcoin, which has been battle-tested quite thoroughly at this point.