Would you care to elaborate? Your assertion implies that arc is going to surpass clojure in popularity. Why do you think so? Personally I think that's unlikely to happen given the traction that clojure has been getting already. Clojure has been designed for practical use and is already being used in real world projects whereas I get the impression that arc is sort of a research project where Paul is just experimenting with some ideas and is not constrained by the desire to do practical work.
It's not a story. It's a paradox. The tortoise loses, but the paradox pitches logic against intuition and is thus educational, like a koan (from a different cultural tradition). I am not sure if it is applicable to Clojure (as well as Arc and lisp in general) where intuition follows logic rather than contradicts it.