Can anyone comment on the state of Typescript - Google Closure integration ?

This is a great question, and to clarify for anyone not following along closely:

Some of us using TypeScript dream of a day when TypeScript emits JavaScript already annotated with type meditations which express as much of the typescript type system as possible in a way that Closure can understand, thereby making it possible for Closure to perform maximally efficient tree shaking and other magic with code that started as TypeScript. Such a thing as necessary and helpful because the addition of this detailed type data makes it possible for Closure to do a much better job that it can do with "just" untyped JavaScript.

https://github.com/angular/tsickle

It's already used within Google to effectively optimize TypeScript apps. However, someone still needs to write the integrations between tsickle and the multitude of public JS build systems and there's not a lot of pressure on me to do it (I have lots of other work to do).