This is great! Really excited to be able to use JSX in TypeScript.

Not sure where best to voice this, so I'll mention it here -- is it a concern that the semantics of as are different in TypeScript compared to C#?

The Facebook devs working on Flow chose to deal with casts by reusing the colon notation, e.g.:

The type annotations used between Flow and TypeScript are very similar otherwise, I'd love to see the similarities grow where possible to potentially improve the odds of ECMAScript standardization as well as tool interoperability.