Another suggestion, I don't know if it would be better for this plugin or for the suggested plugin that will assign tags or any other taxonomy:
Work not only with posts, but also with custom post types.
My use case: I'm pushing a lot of external content into my site (importing RSS through Feedwordpress), kind of creating a database of content. Automatic tagging/taxonomizing of posts/custom types would allow me to create an actual database of content, searchable and indexable, so I can let users do stuff like "get a list of external news (not our own posts) referencing this location and this subject". It could be done with the tagger we have now, but it would be more powerful with these improvements.