If all countries can accepted crypto currencies in there various countries, as a means of payment and as a means of online exchanges, such as money is, money is anything use as a means of exchange and general acceptable. With the means I think all cryptocurrencies (bitcoin) will definitely go round the world, and will be use as a means of exchange. I will be so grateful to the creation of crypto currencies. This will also help our future generation, Remember something when we do international transfer across the countries, it may take a while to get the money to your local bank account, but with cryptocurrency you can get instant reflection if bitcoin etc is transfer to wallet,And you can make use of your coin (bitcoin ETC).
This would have been awesome no doubt ,using bitcoin as a global currency is something every crypto enthusiast want, but the chances of this happening is pretty low or equal to zero, I mean the government will never accept a decentralized currency ,they dislike the people being independent, so that will never happen, although it's possible for a virtual currency to become a global currency, but it will be centralized and controlled by the government.