Clojure is neat and all, but I can't see it being anything but a proving ground for some more esoteric technologies or methods. Lisp has been around too long to get mainstream acceptance and the "power vaccum" of which PG is fond of mentioning is marginal these days due to Ruby, Python, etc. Clojure has the attractiveness of running people's existing infrastructure (i.e. the JVM) but its nowhere near being alone in that regard. Its neat but don't look for it to be a world-changer.