[spankalee]

Yep, we're going to greatly expand our support of TypeScript with Polymer 2.0. We'll have supported type declarations, and decorators to help write elements, and eventually (though maybe not at Polymer 2.0's release) tools support in the Polymer Analyzer and IDE plugins. You'll even be able to type check and auto-complete in your templates.

There's a little dated PR that adds TypeScript decorators here: https://github.com/Polymer/polymer/pull/3954 We're probably going to break out the decorators into a separate packages, since the ECMAScript decorators proposal has diverged a bit from what TypeScript supports now.