[randomThoughts9]

1. I see the the current batch of crypto-currencies as an experiment and their valuation more like a bet on which currency will manage to adapt to the future.

2. Not all properties are relevant or even desirable: For example, I could live without POW or a fixed cap.

3. That being said, let me give you an example of a currency that could realistically be adopted by a government: a centrally controlled currency (the central bank is the only miner) but the blocks are validated by the citizens.

Here you could have the inflation rate specified through a smart contract (e.g. 3%). The only way to print more money would be to to ask the nodes to vote on an amount that will be included in the next block.