Well, it seems good at first glance. But fast-tracking this into the block-chain is probably not a wise idea. There's no rush so it might be prudent to think of this as something for 2 years time or later. Bitcoin is not exploding tomorrow, so there's no big loss from holding off on momentous changes like these.
Actually, I think this is considerably more urgent than that. Right now, it's impossible to safely hold corporate-scale amounts of money in Bitcoin, because corporations can't trust any one person with unrestricted spending power. Botnets have started introducing wallet-harvesting as a standard feature, and the encrypted wallets are
not a defense because they had password-keylogging was a standard feature already. Every large theft deals major damage to Bitcoin's reputation, and if it takes too long to add security features, the damage will be irreparable.
There is going to be an unavoidable delay between hammering out the details of this proposal/group of proposals, and introduction on testnet; another delay between introduction on testnet and introduction to the main client; and then another delay between introduction to the main client and activation in the blockchain to allow miners time to get up to date. These delays are important, but remember that the thing we want to maximize is thought, not time; and there are better ways to get more people thinking about these issues than just waiting. Once the details are hammered out and there's a testnet implementation (which I see little reason *not* to rush; it's only testnet), then it'll be time to summon as much security-researcher attention to it as possible.