Whether this works or not lies largely in the way the Bitcoin software developers pitch their change. For example this cut would be much less directed if you invalidate bitcoins that are older than 3 years. Independent of the Satoshi coins I would favor something like that to clean up lost bitcoin accounts and to shorten the block chain that needs to be cached by all clients. I think Bitcoin is still young enough for such adjustments to work.
The difference between cutting the Satoshi stack and the Crawfurd v. The Royal Bank case IMO is that in the latter invalidating money in active use greatly threatened the viability of the currency whereas in the former the money is just lying around anyway and its existence is a threat to the stability of the currency itself.
For real fungibility with bitcoin we need to add real anonymity, something like zerocoin or some bank like structures that provides huge scale money laundering (in the way this currently works with established money). At the moment bitcoins leave behind such a huge paper trail you can hardly describe any coin as equal to any other, except those freshly minted.
The difference between cutting the Satoshi stack and the Crawfurd v. The Royal Bank case IMO is that in the latter invalidating money in active use greatly threatened the viability of the currency whereas in the former the money is just lying around anyway and its existence is a threat to the stability of the currency itself.
For real fungibility with bitcoin we need to add real anonymity, something like zerocoin or some bank like structures that provides huge scale money laundering (in the way this currently works with established money). At the moment bitcoins leave behind such a huge paper trail you can hardly describe any coin as equal to any other, except those freshly minted.