I won't dare to predict the price in short nor long term, but for sure Bitcoin will lose a lot of power in 2018. It was the first one but there are new cryptocurrencies that are growing, with huge potential, many developers behind, lower fees and faster transaction times. Bitcoin is losing a lot of dominance since May 2017 when Ethereum was released and I'm sure its dominance will continue decreasing. You can see in this figure the dominance of Bitcoin vs Others in 2017.
I won't be surprised if coins like Ethereum have the same market cap than Bitcoin by mid 2018. Will any coin surpass Bitcoin price in 2018?. I don't think so, but who knows.
So I agree with @davidconstantine, 2018 will be the year of altcoins.