Item count in collections
It would be nice to know how many items are contained in each collection, and perhaps in the library itself. Perhaps each entry in the Collections listview could have a "+" column like items in the Item listview, simply displaying the number of items in the collection or library as a whole.
1023 items in 12 subcollections (4321 total items)
Or something that sounds clearer, to give the number of child items as well.