Using the attachment taxonomies to have galleries that automatically build itself thanks to the [mla_gallery] shortcode is such a joy! Thanks so much for this plugin, David. I have no doubt that a lot of people will LOVE you for it! :)
There's one thing I would like to suggest: add an option to show the last 10/20/whatever items that have been added to the media library. That could be used for a "new arrivals" items list, "latest images" gallery, and so on.
Maybe via another shortcode, like [mla_gallery_latest number="20"] or something like that.
Just an idea.
Thanks for looking! :)