This is something I've been wanting for a while now but it would be great if we could copy all the privileges from a category to another category.
A use case for this is for example, I have multiple "moderator" groups on my forum so instead of going and editing every single category I have, I set the permissions in General and then edit my other categories to pull in privileges from General.
EDIT: Additionally, it could be very useful to have the option to apply the privileges from a parent category to all of it's child categories.