I really like this. The inability to share information between the server, stylesheets, and javascript is problematic.

Imagine, for example, using this to semantically declare the frontend elements that your website uses, and thus allowing your server to render them, your css to style them, and your javascript to render/manipulate them, all using the same, DRY data. I much prefer something like elements.user_login_form.class_name to needing to remember / deal with naming conflicts.

edit:

I'd love to see someone mix in some http://lispyscript.com/ with this