An example project implementing TodoMVC with metal-jsx and Typescript. See it running here.
This was made to see how difficult it would be to add a useful amount of type safety to a project using Metal.js, despite there being no existing typings available. I would say the end result was very good. So good thats it's hard to imagine not using something like Typescript (or possibly flow) for any future javascript applications.
$ yarn install
$ npm run build
$ open dist/index.html