I think that cryptocurrencies are probably good news for investment banks and hedge funds. With crypto derivatives now launched there's probably all kinds of investment and arbitrage opportunities, in a space with very little regulation or insider trading constraints, no clear picture of who owns what, or who is manipulating which currencies.
The disruption is likely to be bad news for retail banks, foreign currency retailers and the like: operations that make their money by fees on transactions, or charges on investments. In the same way that the internet was bad news for traditional retail shops. The fees should get whittled down pretty quickly this year.