Clojure is a state-of-the art language on the Java Virtual Machine. Concurrency and multi-threaded development are specifically targeted by the language. If you work on the Java Virtual Machine, you should do yourself a favour and take a look at it.
There are lots of resources online about the language, but if want to learn from Clojure experts, it is possible as a Clojure training will be held in Brussels from 23rd to 25th june in the hotel Mercure Centre Louise.

Members of the Profoss Newsletter can can the early bird registration price, check it out here
Don't hesitate to spread this around you to developers who might be interested.