Ethereum has very high potential for mass adoption.
If you check the ICO market you will see that 90% percent of the new DApps are build on the Ethereum platform, which means that they need Ether to pay for smart contracts which are deployed in the network.
I believe that Etherium will have a positive uptrend because of its usage.
The team behind it is always looking for updates and repaying the majority of developers who come with brand new ideas - This year they will implement the Raiden Network - Faster transactions.
Large adoption is coming towards Etherium, for the moment i dont think they are ready to support 70.000 transactions per second as VISA does, but new times are coming, new ideas are rising and people start to understand the technology better.
I can see Ether in 2018 reaching 2000 $