Multisig addresses are not useful as-is. External tools of some sort are required.
The reference implementation could be improved to be sure, but it will never be able to be the whole infrastructure for multisig.
As jgarzik notes, there are tools available already that are suitable for infrequent multisig usage.
The thing is, if bitcoind would simply include multi-sig transactions in the balance of each account, this entire problem goes away doesn't it?