What I would hope is that these features get rolled back into Java. Xtend could be a testing ground that shows how something would work, similar to the way browsers have their own proprietary implementations of an idea that then serve as examples to the W3C.
I find it sad that some view JVM languages which aren't Java as a testing ground for features which could be added to Java. Other JVM languages are worthy of usage independent of the Java language. Not everything can be back-ported to Java and keep the language backward compatible.
