Ability to create a Folder View that contains selected objects for ease of management. For example, if I'm working on an inventory process, I'd like to have all associated procs, tables, view, synonyms etc all be grouped under one folder for ease of access.. You would essentially create a filter for the "Folder View" or you can right click on each object and add it to that view. This new folder will show up in the object navigator.

This is a feature that was available on a product called PL/SQL Developer which I found to be extremely handy when I was working on Oracle Based projects.