There are a few language enhancements. It's true the 9 isn't a revolutionary release for the Java language, but there are several useful changes.
This[1] is the best summary of what is in the release that I've read. The first section discusses language enhancements. Lots of cross references to JSRs and other material.
There is not going to be a Java 10. The next version of Java will be 18.3, to be released in March '18, followed by a release every 6 months. Those will not be "Java 9 feature releases" but "major" Java releases.
well, most of my java projects tend to be very broad in scope, so in those cases, it can potentially make a major impact in systems and API designs.. I'm being optimistic!
While I don't disagree, I do think there's a general lack of empathy here; we're so overloaded with information, our senses are always tingling at 11/10, making it even more difficult to understand others or appreciate their version of the human condition.