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).
Not sure if the speed of depositing my money into a bank account has the same speed as sending transactions in Bitcoin, but I don't think it will ever be the same as both of it.
Bitcoin can be exchanged to fiat money but it is gonna be a bit tough to be adopted as a means of payment to some merchants due to volatility of the price as we know it.