There's a similar tool at http://color-theme-select.heroku.com it's also in beta, allowing to generate custom themes and select from a large collection of them. I've contacted the author to see if he's fixing the "generate emacs-lisp" feature.
Would be nice people could use that tool to create themes for emacs 24, and send them to emacs-devel.
http://twitter.com/vborja/status/22350595050438657
Awesome!! seems to work like from __future__ in python.