I think Bitcoin will be here for a few more years but after that it's anybody's guess. Blockchain is the true revolution not Bitcoin. It's yet to be determined which cryptocurrencies will be here for the long run. Let's face it Bitcoin didn't have any real value until it was adopted by drug dealers, money launderers and gambling websites. Now it's in the next stage to see if it has legitimate uses such as microtransactions and serving as a currency in third world countries that face hyperinflation. Who knows? Maybe the vice world will push more anonymous currencies like Dash and Monero to the top of the list of most used cryptocurrencies?