I'm genuinely curious. What about the language do you feel is "ossified"? I am interpreting that as being a negative description.

Stability is extremely valuable. A lack of change to the core language over extended periods of time can be a very good thing, especially if certain changes would break existing code. Rich has made it clear that he is indeed targeting this kind of stability.

Again, I would be very interested to hear what specific changes you think need to be made to 'Clojure "the language"'.