While having a lot of categories will make them ineffective and useless, but we need to expand the current set!
I think there was some discussion started by @EricShulman in Google Forum about a suitable set of categories (i.e. tags or labels)
He even discussed cases such as singular or plural names for tags (e.g. plugin or plugins etc.)
I may recommend having that experience expand the current set of categories!
Some crude suggestion:
theme, filter, palette, template, macro
bug, announcement, tip