Interesting; why do you see Clojure as more geared towards that goal than Arc? Although I haven't used Clojure, it seems like more of a compromise intended to bring Lisp to the JVM than a language designed to last into the next century.
What about Clojure strikes you as being a 'compromise intended to bring Lisp to the JVM'?
This very much suggests that Clojure is trying to solve today's problems, not those 100 years in the future.