I wonder how this will affect Java in the long term. In the comments about the JDK9 release, there was discussion about the JVM becoming a sort of language-agnostic platform where Java is a small part. It seems WebAssembly is occupying a lot of the same space, but from a sort of opposite direction (in the sense of providing the compilation target first).

Java and the JVM obviously aren't going anywhere soon, but the history of javascript, node.js, etc. leads me to suspect WebAssembly could displace the JVM in the long term.