I was just thinking about how one would go about creating a sub-currency/smart property that could be exchanged via a decentralized exchange.
Since there will (hopefully) be many types of properties that people would like to exchange, no exchange application would want to implement a different system for each type. This leads me to believe that an exchange would develop a certain protocol by which the property contract would have to be developed in order to be traded on that exchange.
I'm not really sure if this would work though. I'm not sure how the exchange would be able to trust some random property contract. The exchange might still need human inspection of each contract in order to be added to an exchange. A possible solution, could be that a contract would have to register with an exchange with an initial tx in which the exchange contract would send a few transactions to make sure the property contract actually follows it's protocol. The problem here is that the contract can be coded to pass the test and then do other things later. Even changing the contract code is possible.
Any ideas? Perhaps the very fact that Ethereum gives the developer so much control means that it can't truly be a trustless (contracts not the Blcokchain) environment.