I'm working on a React powered "isomorphic" static site generator now and I hope to make it public in the next few days.
The approach I'm taking is that each page is a composed component using data files (json, yaml and js/coffee for dynamic data) to provide the state, js/coffee mixin files to provide the logic and js/jsx/coffee/cjsx files to render the body content.
Its working now but I need to generate the documentation and built some better example sites.