This project was just provisioned. You can see the proposal here
JS4EMF supports attaching extra methods to your EClasses, to make scripting even easier. Extra methods can either be embedded in the model using annotations or in separate js-files. Existing EMF classes, like EObject, EEList and EClass have already been extended, for your convenience.
JS4EMF is currently in the Validation (Incubation) Phase.
We're in the process of moving code from e4, cleaning up the API and improving the tests and documentation. A release is planned for the first half of 2011.