No I dont think that Bitcoin will replace the Dollar soon, because till now the most part of people worldwide still using fiat and also Bitcoin isn't yet supported everywhere online and offline, and not even legalized in some countries.
yes that is right that it is not so easy to replace dollar i think that it will take some time. but still it is going to happen because still there are lot of potential to increase it price. and i am sure that it will continue for a long long time. i am sure that very soon the users of bitcoin will continue increase too much, because people are still interested in bitcoin.