All, as you know, we have been keeping step with the Angular team throughout the process of releasing Angular version 2.
We are still committed to supporting Angular version 4 (and more)! We are working hard to migrate to TypeScript 2.2 as well as Angular version 4. We will provide a preview build as soon as it is stable and officially release shortly after.
Congrats to the Angular team for shipping version 4. And thanks for your patience as we finish our Angular 4 support.