The world has one global currency, I think it's impossible. To make everyone have the same thought is impossible, and surely there will always be those who oppose or support, and it will be difficult to make one global currency.
Dollars has much power than bitcoins open the chart now and see where is bitcoin is now. Market is down. Peoples deals with dollars not with bitcoins. I am not against bitcoin i love it but its hard for bitcoin.
That much is obvious, the US dollar is the strongest currency around the world but that is not going to last forever, we had strong currencies that seemed impossible to replace in the past and they were replaced and when there is something as good as bitcoin waiting in the sidelines just waiting for an opportunity to grow then I will not be so confident this state of affairs is going to last for long.