By the way AngularJS 2.0 based on Typescript not ES6.

It's not clear on what angular 2.0 will be based, the more the angular team talks the unclearer it is :

http://i.imgur.com/upcrFbi.png

this is a slide from ngconf.

Yeah that slide is a little confusing because they messed up the second step. JS Facade is supposed to be where Dart Facade is and vice versa.

Also, Angular 2.0 is going to be written in TypeScript (which will be compiled to plain JS) but you can use ES5, ES6, TypeScript or Dart depending on what you want to use for your application.

TypeScript could be compiled to ES5 and ES6 (--target ES6).