This model usually works pretty well for smaller components (see http://facebook.github.io/react/blog/2013/11/05/thinking-in-...)

For larger ones, we provide lifecycle hooks so you can set up these subscriptions manually. In componentDidMount() and componentWillUnmount() you can subscribe/unsubscribe to some sort of messaging system, and when you receive the message call setState(). Usually you only need to do this in a few places and the regular React dataflow will carry you the rest of the way.

Does that make sense? We should probably write up this technique.