There's not going to be any interesting features around the type system. There's no change in the type system. Javascript is still a prototype based language.

There's not going to be any interesting features around the type system. There's no change in the type system. Javascript is still a prototype based language. There's no real value to a class system in a dynamic language, beyond synthetic sugar. Arguable prototypes are better since you don't get to question "if everything is an object, and classes are objects then what class is a class of?" With ES7 decorators, you can put a mixin into a class... which gives you class sugar + traits, so essentially multiple inheritance without the downsides of it. ES7 can be enabled today via Babel.