I'd like to see a header sort widget like previously was possible for list view.
This would make it possible to click on a custom styled column header bar on top of the gallery widget, and sort on a single attribute when you click on the header. Perhaps you could even combine multiple headers at once.
The dropdown sort widget is nice, but it's sometimes not exactly what users expect in terms of UI. For instance when you need to have a data grid look and feel, but with the custom flexibility of a listview.