If you want to use it now and get full browser support, you can use the TypeScript compiler, which will compile into ES3 or ES5 targets. It also supports ECMAScript 6's classes syntax.
It's pretty neat to use this tech now on production sites and not having to worry about browser support.
It's pretty neat to use this tech now on production sites and not having to worry about browser support.
http://en.wikipedia.org/wiki/TypeScript#ECMAScript_6_support