Possibly. It will happen anytime soon. The only way it could crash the US dollar would be if most Americans adopted Bit Coin and stopped using the Dollar. Very few people understand what Bit Coin is or what it does. Even fewer are willing to buy it or use it for transactions. Also, if global trades start using bitcoin then that will big hit to dollar.
I hope that someday a decentralized BitCoin takes out the dollar. The common man will certainly benefit from that. But don't get too excited we are a long way from taking out the governments filthy mammon.