I was reading up on the next version of Javascript, called by several names: ES6 (EcmaScript 6), ES.next, Harmony etc.

The official name is EcmaScript 6 or ES6 for short.
It offeres improved support for larger JavaScript applications, by adding classes, typing, modules, lambda expressions, default values for parameters, new collectiontypes and operations etcetera.

The standard can be found here.

You can use parts of it already in several browsers, or you can use cross-compilers like typescript or Traceur.

One of the new things I learned is you can use it already with node by adding a startup parameter.

node [yourapp].js --harmony

If you want to start reading more, start with this:
It is a really nice summary and contains links to more material.