I don't think so; it will surely get huge, but it will never be going to be replaced with the dollar.

If it is by any chance, that will cause a lot of confusion in people.

For example, you're buying something, and the seller says it costs you 1Dollar, that's normal. When bitcoin replaces the dollar and he converts that 1dollar to Bitcoin every hour the price changes? And people will surely have no idea how much it exactly costs in their currency, either the seller has to convert it to the USD too.