I see very very less chance of it happening. Because bitcoin is the pioneer in crypto currency world. The market cap is already huge which shows the interest of the people in bitcoin. So it is hard to replace bitcoin.

But on the other hand I won't say that it is impossible. You may have some other crypto currency which may grow up to bitcoin's level in future but probably that currency won't have the power to replace it. It is just that people will start enjoying the fruits of that currency as well. That will be only good for the crypto currency world only.