I'm interested in this too. What I've been wanting is a single chip solution.
I've designed various systems based on arm7 chips, but my naive lisp implementations barely fit any usable system into the onboard RAM (~90k).
I've been waiting for atmel or someone to put something like 1MB or so on chip, but the market for such devices isn't there.
FORTH seems better able to fit and has a little better fundamental underpinnings than BASIC.