Few months ago, a prototype of GUI for Augeas was posted on the augeas-devel mailing list. I found it awesome, so I wanted to take it further. I think this is the kind of tool that can easy the configuration management on Linux, like regedit does on Windows. It's still require knowledge of what you're doing, but at least, you don't need to worry about the syntax of a particular config file! Here is a screenshot of the latest version.
Some of ideas that this kind of tool should have: basic edit operations (add, modify, move, delete, ...) searching, filtering, bookmarks, auto-completion.
If you want to try it, you will need the "myhead" branch of augeas, up to date python-augeas branch "aug_info" that adds the API function for highlighting, and the code of Augedit itself.
Leave your ideas about this tool in comments! ;)