I will say I've found Clojure to be a success story for doing GUI work. Projects like Dave Ray's seesaw (https://github.com/clj-commons/seesaw) are an amazing demo of how one man can rearchitect an API like Swing into something that is deceptively fun to use. High hopes that this project goes somewhere that is similarly enjoyable.
http://groovy-lang.org/dsls.html#swingbuilder https://github.com/scala/scala-swing