We've been toying with the idea of a 'dead' button, one that issues a bunch of pre-generated txs sending stuff out to a previously secured 'backup' set of addresses (we don't think in terms of wallets, just keypairs).
In this scenario, you have a long-term storage address (or set of them), and if you need to hit the panic button, previously signed transactions send value over to your emergency storage.
If you've mucked around sending / receiving with your long-term storage, you'd only catch some BTC, not necessarily all, but what's nice is the panic transaction leaking has lower security requirements than your private keys -- worst case it's out, and you've got to deal with stuff in emergency storage, as opposed to losing all your coins.
You could pair this with a server that checks if 'safe' addresses have 'unauthorized' transactions showing up on the blockchain, and you'd have a reasonable automated security layer. Maybe. :)
I'm interested in thoughts on this approach as well.
Jorge -- I respectfully disagree with you, there are a number of enterprise scenarios where your method is not appropriate.