I played around with the idea of giving Star Wars the treatment, maybe with the Force giving you super-rationality powers (and then there's always Grand Admiral Thrawn), but I don't expect to get around actually doing it. I also suspect I'd need to rewrite half of the SW universe to make it work.
I've enjoyed your work in the past, I think that the genre could benefit from your entrance.
I've been enjoying reading Less Wrong fanfiction, and I wanted to suggest another fandom that should have at least one rationalist fanfiction: Mage: The Awakening. It's a roleplaying game about "modern sorcery." My description can't really do it justice...