I dont think so that the Bitcoin will replace the dollar and that is because there are now a lot of people that is waiting for a price increase and not many people dont even know what Bitcoin is so that have to change.
And you can not pay everywhere with Bitcoin so that is also a big problem of the currency.
In the future I think but not soon, that future I am talking is maybe around 20 to 30 years from now, with the continuous support of bitcoins that can be possible and we should rip the fruits of our investment if that will happen as the price will increase substantially.