In JWT, we've been working on 2 features for the JWT workflow editor
(which is based on EMF), and it seems to me that they are more generic
than JWT context.
Those feature are
* An extension point allowing to set a custom PropertyDescriptor in
property sheet for specified EMF feature (to facilitate the input of
properties for end-users) (bug 240499)
* An extension point that allows to add a INotifyChangedListener on
specified feature (we currently use it for value validation, and to
compute some properties automatically) (bug 240502)
We think that such features could be interesting for EMF generally,
that's why I spot them out (bug 240499 is closed to bug 205432).
If you think that they deserve to become part of EMF, we would be
pleased to participate to their integration in EMF. If you think that
they would not fit in EMF, sorry for the spam ;)