>Hopefully someone will find time to take the best of these two Lisp dialects and create a new language in the future that rethinks "brevity" in terms of the ideas behind Clojure.
I'm curious which particular ideas you're talking about? I've used both and I don't know what clojure brings to the table that arc really needs, besides the stuff that arc will certainly get anyway, like libraries, some kind of module system, and facilities for performance tuning. (Although I think clojure could use some better libraries, too :)