Bitcoin will survive and will continue to exist, just that its price will become too expensive to be purchased. If this total supply of bitcoin be reached, it will take a long time, and even if that time is come, some way, somehow, the backers/minds behind bitcoins development will think of something. New ideas will have to come up for the use of bitcoin, and at that time, bitcoin would become an investment project, where the price could be so strong, that the fluctuations in price will not be much again.