I predict the price will continue to rise on average for the next 1-5 years, although it might start slowing. At some point between 10 and 25 years, Bitcoin will experience a major crash. Whether it stabilizes into some sort of useful medium of exchange alongside competing cryptocurrencies is hard to predict. It might survive in a limited role or a limited market, the value of which is very hard to imagine at this point.
In 100 years I think bitcoin will be worthless.