It would be awesome if there was a panel/toolbar in ArcCatalog that showed the files that refer to a selected data source. The panel could also have the option to update the path within these files when the data is moved.
For instance, you need to relocate a shapefile that used in several different maps in different folders. This panel could access all your maps and update the data source path in all of them with a simple dialog, rather than having to open each map individually.