when will the p2p exchange be built?
The answer is easy. Never!
P2p exchanges are only possible if you exchange p2p currencies. Fiat is meant to be centralized as much as possible. That is, if you attempt to handle fiat in p2p way you'll break a dozen of laws and regulations in every country!
It is possible to exchange value backed by crypto-currencies but denominated in fiat at full face value + interest.
The *key* is to back the fiat-iou with crypto-currency collateral. If someone 'defaults' on the fiat-iou they end up losing 2x that value to the network.
I posted this idea in one of the child boards but it hasn't gotten enough visibility.
https://bitcointalksearch.org/topic/m.2238954A quick summary is this:
1) all balances (fiat or otherwise) pay interest
2) all fiat balances are created by someone borrowing against a crypto-currency used as collateral.
3) payments from the collateral are distributed to those who hold a balance in that fiat currency.
4) people borrow against their crypto-currency because they expect it to go up in value relative to fiat AND the crypto-currency also pays dividends from transaction fees.
5) once you have a fiat balance it can be traded as easily as a bitcoin balance.
6) fiat balances are always 100% redeemable at face value (excluding transaction fees) so long as the underlying crypto-currency maintains any amount of value.
7) the effective interest rate on fiat balances goes UP when the value of the crypto currency goes up.
Given my approach we can now eliminate the centralized exchange. Allow individuals acting as 'local-bitcoin operators' or posting on craigslist to 'deposit' and 'withdraw' $USD or EUR from other individuals without having exchange risk but only a potential 'transaction fee'. There would be more people wanting to deposit $USD because their $USD balances pay interest and with more people wanting to deposit that means more people wanting to withdraw which equals more opportunities for local exchanges. People could use the system without ever owning an asset denominated in a crypto-currency to trade $USD among themselves, etc.
The problem with fiat isn't the fiat, but the laws. The way you fix laws is to make breaking them so easy and hard to find and desirable to so many people that they effectively nullify the law. Copyright is effectively nullified by mass law-breaking and that is enabled by the internet. Sure some people get caught, but most do not. There are so many people doing it because it is 'profitable' to them that attempts to shut it down will be fruitless.