I think it's all fine and dandy, and I like the idea of isolated components, but I'm not sold on shoving everything into one file. It just smacks of preference.
So split it up. Most React projects make use of Webpack or Browserify, or use ES6 modules via Babel. There are emerging patterns for keeping concerns in separate places but still having one component you can drop in declaratively.
Then just put all the files for a component into a single folder, which translates 1 to 1. Again, this is all just a matter of preference, and with pre-compilers you could glob all your js/css/html into one file using any framework if you really wanted to. Seems silly to me, but to each their own.
