OOjs provides class inheritance in ES5 environments. As we eventually move to an ES6 world, that part of the library will become redundant, but other parts may remain useful.
ES6 class inheritance works very similarly to OOjs's, and most features should continue to work out of the box (including the static property).
Mixins may need some work to continue being supported as classes, as OOjs assumes the class prototype is iterable, which it isn't in ES6. It may not make sense to keep defining mixins as classes, but a new standard that is supported by OO.mixinClass should be defined.
OOjs also contains other features:
- Event emitters
- Registries
- Factories
- Various utility methods for handling objects/arrays, some of which may eventually be redundant in later versions of ES
All these features should be tested with ES6 classes.