Was long assumed that something similar will happen. The forum was the discussion on this topic. United cryptocurrency and payment system. The idea is very promising and better able to develop the structure of financial relations. Read about this and find out about a particular mechanism called localbitcoins, because it is the exchange of cryptocurrency for Fiat. But he can't work the same in different countries due to the policies of the banking options in every country in the world. For example, different situation with limits and withdrawal amount. Various legislation and other issues that will seriously interfere with the idea to develop. I think it will be a long time before this area will cover most of the world. And in the end everyone will be able to use this tool. So, as they say, time will tell.