Tail calls, value types, easier direct calls to C to process large regions of data without copying (e.g. lapack): there are many things which could benefit non-Java languages on the JVM like Clojure and Scala that are taking too long with Oracle stewardship (as they did with Sun's as well). Maybe these things are in fact too hard to implement for small or unfunded groups?

I hope not, I think it's high time.