I've been using a fine little plugin to help manage a large list of hierarchical categories in the edit and write posts admin screens. I found it here:
It is great! Long category lists in the write screens are collapsed to only the top level categories, accompanied + icons. Click on a + and the subcategories open.
The only problem is that the plugin is no longer supported and it doesn't work in the new bulk edit box.
Are there any alternatives, or is anyone able to take on maintenance?