> Java 8 (and 9 to come) is the elephant in the room, hopefully won't crush alternate JVM language adoption, diversity's a good thing.

While I agree, I also think that some of the less hardcore JVM languages (Kotlin, Ceylon etc) were mainly developed because of how stale Java itself became / is; even Java 8 only adds very basic support and use cases for lambdas, mostly to retain backwards compatibility with existing libraries.