What's interesting about this ruling with respect to Ethereum is that one of the main reasons Ethereum has done so well is because of the development team. If they were terrible, Ethereum investors could have lost all of their money, but instead the developers have done a wonderful job and that has resulted in substantial profits for those holding ether.
The investors do not get dividends or equity, but they absolutely have invested in a common enterprise (Ethereum, the Ethereum network, and the Ethereum codebase) with an expectation of profit (obviously) based on the efforts of a third party (the developers - who control the entire codebase and have moved Ethereum forward every step of the way).
Although this ruling is obviously good news for Ethereum, it seems to set a bit of a double standard with respect to what we've seen about Ethereum tokens, where the situation is very similar to this, but yet they're instead ruled as being securities due to the above reasons. It is interesting that one of the key points here is their notice of 'decentralization' - how much decentralization is required for something to not be a security? It's a very difficult question, because development is generally always centralized in any project, there's few other ways to get things done efficiently.
The price of Ethereum is up almost 10% in the last 24 hours, partially related to this news as we see a spike in price coinciding with this announcement across the market (https://coinmarketcap.com/).