While I don't doubt Clojure 1.3 can get similar performance to Java, that's not what this benchmark shows. The Java and Clojure functions he's comparing don't even take and return the same argument types. He's comparing boxed Integers to primitive longs.

In the comments he says he saw no difference between Integer and ints. When I ran Tak.java with longs like the Clojure code my time went from 13s to 8s.