Groovy in the Light of Java 8

With Java 8 out the door, Java developers can, at last, benefit from the long-awaited lambdas, to taste the newly-found functional flavor of the language. Streams are there to work more easily and efficiently with heaps of data.

Those things are not new to developers acquainted with Groovy. But what is left to Groovy to make it attractive beyond all the aspects Java has caught up with Groovy?