Idea:
A configuration can have a 'extends' property defining a path (absolute or relative) to an other configuration node which he wants to extend.

Implementation:
A content wrapper similar to the ones used for inheritance or i18n will combine the configuration and expose the merged content to content2bean transparently or potentially also to other mechanism as like the dialog manager. It will potentially also be a successor of the 'reference' property used to define dialogs.

Note: this is a bit different from what we do in STK for merging the template and template-prototype. There we merge the already instantiated beans.