Now that we have a way to call Emacs functions from Guile, we could develop a system which translates Emacs Lisp to Guile Scheme and runs it in Guile. I know Guile has some primitives (null, nil-cdr) to help with this; is there already some Scheme code for the translation?
You could look at the branch in the Guile repository tagged "mdj_elisp_branch". In the "lang" directory, elisp.scm is intended to let you load or evaluate Lisp, specifying the use of elisp syntax transformations that convert it to Scheme. It's also a problem that Michael Sperber's group is working on for XEmacs, though not targetting Guile specifically.