cunicula, you're right. I should clarify.
I didn't mean to say that the concept of a public transaction history with a trusted timestamp mechanism should be tossed away. I just meant that proof-of-work as the mechanism for establishing trust would be rendered effectively useless.
You could still have a mechanism based on web-of-trust and reputation.
I agree that a web-of-trust and reputation is a solid mechanism for organizing exchange and decision-making, but I made a different point than this...
Another time tested mechanism is to allow voting based on proof-of-ownership. That is how corporations work. They seem to do all right in terms of serving the interests of their shareholders.
I am recommending that bitcoin or an altchain work in the same way. I describe how this voting mechanism could be used to organize a blockchain in the proof-of-stake wiki.
https://en.bitcoin.it/wiki/Proof_of_StakeYou should consider checking it out. It is a really simple design.