Lightweight Threads, Channels and Actors for the JVM: http://blog.paralleluniverse.co/post/49445260575/quasar-puls...
Though as the Node people occasionally point out, it is advantageous to have this sort of thing baked into the language, so that everything done in the language supports the concepts, rather than having a relatively small corner support it. Plus you get Go, instead of Java, which I for one would find an improvement.