> This breaks code editors, static analysis tools like jshint etc.

You're right. One of our goals in the coming months is to try to make some language files for editors. Vim actually does a pretty good job of this already thanks to the similarity to E4X.

JSHint is another thing we'd like to improve upon. At Facebook & Instagram, we actually lint against the transformed code. Right now the transforms don't modify line numbers so it's been easy to match up. We'd like to build some tooling around this for people who make use of React and JSX.

> I think Web Components is landing soon, and this seems like it could leverage that.

I like the way you think! We've started thinking about that already.

Any chance of having CoffeeScript integration? Instead of inlining straight XML, can we wrap it in a function call (like gettext style) so it does not break existing languages/editors?