today Kotlin compiles to Java 6 bytecodes what prevents usage of JVM improvements like invoke-dynamic or lambda support. Java 9 will bring as modularization, namely project jigsaw; will Kotlin be able to use this module system? What are the general plans to keep up with the Java evolution? Would it be an option to have different compile targets (jdk 6, 7, 8, …) at the same time?
Not ready to talk dates here, but Jigsaw will be supported closer to the release of Java 9, i.e. in a year from now. And due to its compatibility design, you can use Kotlin with Jigsaw right now as if it were plain old Java code