Topics about market trends generally don't go in this forum, so try to keep the talk away from that.  My hope is that 2018 will finally mark the possibility of Bitcoin supporting ACCT, or Atomic Cross Chain Transactions, so that users finally won't have to rely on centralised exchanges to trade altcoins and hop between different blockchains.  Then again, I thought 2016 and 2017 might mark the year that happened too, so maybe I should rein in my boundless optimism and enthusiasm for that feature and just enjoy it if or when it eventually arrives.

But other than that, it's probably going to be more of the same.  More contentious fork proposals because no one agrees on scaling, the traditional finance sector continuing to make bets from the sidelines while pretending they're actually involved in some meaningful way, ICOs out the wazoo, the media focusing solely on the fiat price despite the part where that's actually the least important aspect, etc.

I'm also thinking people will continue to misuse the phrase "mass-adoption" in 2018.  Bitcoin is still nowhere near that, despite our combined best wishes.