I'm pretty heavily involved with LispNYC, and they're the lispiest of the Google SoC sponsoring organizations. I'm also pretty interested in psyco, so if someone finds a student who wants to work on this, I'd be happy to mentor.
LispNYC ( a lisp user group in New York ) has, in the last year or so, seen the debut of at least 3 lisps: otter by perry metzger, clojure by rich hickey, and nyclisp by me. Nyclisp is by far the least mature, but I'm trying to clean it up a bit for a release.