An article about throwing away the Internet and starting over seems a bit off. First, it complains about spam and suggests that we need to throw the Internet away to combat spam. Aside from the need to politely ask the global economy to grind to a halt for bug fixes, this really seems like a case of pulling out the ICBMs to hunt cock roaches. While I admittedly don't know much about the adminstrative side of things, I don't see why adopting a new email protocol requires scrapping the 'Net.
The author also wrote "Conversely, whitelisting would become easier because you could whitelist users based on their certificates, not based on a from: address that is easily spoofed."
Yes, the from: address is easily spoofed. If you spoof email to me from my friends and I have a whitelist in place that allows those through, you can spam me. Now imagine trying to send out 10,000,000 with my friends email addresses. If everyone had whitelists, that spam would be useless and thus not cost-effective. Spammers would have to try to figure out not just how to spoof headers, but how to figure out which email addresses large percentages of users are going to allow through. I don't imagine enough overlap that this would make spamming cost-effective.