I've just tried out sorting, filtering and bulk edit - looks great! It makes working on a catalog so much less frustrating. I like the way the more/less links on the quick edit select boxes work too. For a new recording I have over 100 Works to select from so being able to expand the list is a good thing.
If you wanted a further challenge ...
How about some functionality that presents only relevant taxonomy names?
I have a hierarchy of say Works - Movements - Recordings. All are custom post types, Works and Movements are CPT-onomies.
When I create a new Recording, I assign one (or more) Works from the list, then I may optionally assign one or more Movements. At the moment all the Movements are displayed. It would be good to see only those Movements that have previously been attached to the current Work.
I could see this sort of thing being valuable any time you have a strict one-to-many hierarchy and you want to enforce a degree of data integrity. It would mean you could lock down your taxonomies and protect the data structure from your users!!
I could see it working like this:
Create a new recording. The Works list is fully populated so go and select one. As soon as you have selected one, the Movements list is populated by the Movements that are assigned to the Work. Select one and you're done.
Obviously it wouldn't work if there wasn't a strict one-to-many hierarchy between taxonomies. It wouldn't work for Films - Actors for example. It could work for Books - Chapters - Illustrations, or Author - Books - Editions.