Ethereum and ether are two different thing. Ethereum is a blockchain network that you can use to deploy 'smart contracts' which are just immutable bits of code that run over the decentralized network. Ether is a token required to use a contract to prevent DDOSing. Ether is not supposed to be used as a currency, it is basically like bandwidth, you can pay more to do more on the network. With smart contracts you can make your own tokens, which may or may not be currency. As of right now there isn't a unanimous token for being used as currency, so people that believe in ethereum are just using ether right now. It's a pretty interesting project, you should check it out.