I've been creating an application with Meteor and React* and it has been pretty easy thus far. Although I'm not using the official Meteor-React package, it does a lot of the same things that the official package does. The unofficial package also uses a mixin to use with React classes.
I would love to see this. I really love flux and want to get flux into it, not just react. If it's open source, I'd really appreciate a github link :D.
*edit: Meant to say React instead of flux