Wait, you write "If Satoshi attempts to spend his coins, this might reveal his identity", but, would that now contradict the claim of anonymity in bitcoin transaction?
There is no anonymity in Bitcoin. There are ways to go about this, such as selling BTC for LTC and then back to BTC, and there's been a suggested modification to Bitcoin called zerocoin that would make it anonymous, but by itself, Bitcoin is not anonymous.
I think US paper currency, aka the Dollar, provides for anonymity. If one pays with paper bills and coins rather than by electronic means, anonymity can be fairly effected.
