I don't understand why people are so keen on clinging to hyperinflated paper money, especially with what has just happened in Detroit. A decentralised stock exchange I think would be entirely possible if it was just in cryptocurrencies. In fact just about anything can be possible in cryptocurrencies as long as it's all open source. The problem is though you're all trying to re-write the rulebook for paper money when central banks have it locked away in a safe under armed guard. I think it's pretty pointless, the only way you could make this work is if you found a friendly country to exchange money in, even then they are bound to come under all sorts of political pressure and maybe even embargo's etc. until they change.
Stick with precious metals and cryptocurrencies, the current system is a dying one and if they aren't going to be diplomatic with us I don't see why we should with them.
Think of it more as backward compatibility to help with the transition. While most people around here understand the problems with fiat, it doesn't change the fact that most businesses dealing with the public face exchange rate risks and that we need a transparent price discovery system.
BitShares will also handle gold, silver, oil, gas, APPL, and any other asset class. But it will take 10+ years of unhindered growth (or perhaps hyperinflation) before people will switch to a new unit of measure from what they have grown up with.