I think that's part of what PommeDeTerre is asking; is there any oxygen left over for a JVM Scheme variant in a world with Scala and Clojure? (And an already-existing line of other languages trailing behind them.)
If this were just some other open source project, I'd say go nuts, but we've got a guy here who presumably could get a very good job volunteering to live on raman for 4-6 months to do this thing, so I think this question needs to be considered, even if the answer is ultimately "yes".