One could ask: after Bernie Madoff how could you ever trust a fund manager again?
At some point Visa or Bank of America will start exchanging bit coins and change very high fees. They will have the same internal controls they use for the rest of their business. We don't need any innovation. The old processes work today and will work in the future. We need some company who knows how to run a transactional financial service to set up a service for bit coins. This does not exist today.