The practical problem in creating a bitcoin bank is who is going to handle it and how it is going to organized sector which very complicated thing. So bitcoin bank is not going to happen atleast for next 5 years. One thing will be sure happen All banks will accept bitcoin with all country government approval will be there. Lot of thing is not practically solved with bitcoin due to the rate if we get into all these things it will affect bitcoin performance and investor will not gain like now in future. It is better for us to only upgrade technical things only not in the corrupted banking system.