Nice idea in theory but difficult to implement efficiently combining and minifying of javascript with no errors and correct order of file dependency in a content management system where a page may contain any number of arbitrary built in or custom features.
Probably not going to happen any time soon. I leave it up to developers to manage scripts for their own custom features and we will manage any needed scripts for features we ship. We already have a way for designers to include scripts for design in layout.master.
Best,
Joe