Ether is designed to be fuel for the Dapp ecosystem. It is not a currency. It was never designed to be a currency, and future development will not be focused on it being a currency. It's great in the mid-term because it has great prospects and provides a stable place to store value. However, over the long term, people looking for a currency for exchanging will look to use a more appropriate "currency".

I think the "currency" they choose will be based on the type of transaction. Bitcoin is great for large transfers, but it's slow and expensive to transfer. This is where currencies like Dash and others really stand to shine.