Yesterday on the #rubinius-channel, me, Evan and MenTaLguY had the beginnings of a discussion about a Lisp dialect for the Rubinius VM. Since this sound exactly like the kind of thing I've been thinking about for some time, I got excited. But anyway, Pat Eyler covered the issue much better and did a small interview with us that can be read here. Ruby is wonderful. Rubinius is sweet. With Lisp added to the mix, it will be better.
I'll probably follow this up with some more information and ideas, as soon it's fleshed out.