Another addition to the standard are sets and maps. Sets are simple
collections of objects, maps key-value collections. Both can be used with the new for value of object statement.
The new destructuring syntax works similar as the definition of arrays or objects, just the other way round. So you can define variables in a similar notation and assign this to an existing array or object to set the values of multiple variables at once and with optional default values.
Fat arrow functions are also known in other languages, they can be used to define functions in a concise way and have a different binding behavior.
In addition to the default function level scope isolation, the new keyword let enables block scoping. This may be useful, but could also create a lot of confusion due to the dual existence of two concepts.
The last bigger block was dedicated to generator functions. This kind of function can be paused and return their value later. This can be used for asynchronuous programming, in conjunction with the concept of promises.
So there are a lot of new features, which can make life easier for developers. But it will take some time until those features are supported natively by all major browsers, probably mid or end 2015. Until then you have to use a precompiler.