Ethereum. ETH will empower anywebsite with digital currency, and steemit will be useless since all website will have this functionality.
It's fascinating to observe this growing myth about Ethereum. People tend to get exited how Ethereum will empower them but notice how general those statements always are.
In reality Ethereum is just an empty space (plus exposure to a large number of users) but if you don't have a good idea for a smart-contract, Ethereum will not fill this gap for you. Quite the opposite - there will be fierce competition, so that weak or badly executed ideas will die quickly.
With Ethereum you can (virtually) create your own cryptocurrency, with the supply you want. Websites like pinterest, howto, makeuseof, instructables could now have same functionality as steemit in no time. Even if I like steemit is not a winner there are a lot a things a community like this should have. For example, content templates, for each type of content: article, how to, question, discussion. The post I did "Why Steem Will Fall" it's not intended to be the truth but just a list of weak points and community teaser. As a result for now I can see only flat answers, no real solutions. But there is movement and this is good. Things don't happen, people make it to.
That's the point - they could not have the same functionality.
Adding a crypto-currency to a website is trivial and Ethereum is not needed for this.
What is not trivial is to make a financial ecosystem which a new user can join without making an initial investment. This is something that cannot be replicated (unless you port Steem into Ethereum - but it's not possible as Ethereum requires the existence of transaction fees).