So here are some screenshots from the sample that's using the SmartList control from the SDF v1.1:

As I've already written the SmartList implements a quick filtering functinality a-la Contacts app in Smartphone as well as ability to create auto numbering menus. 

To help you with a quick filtering there're a two new events for your use: FilteringStarted and FilteringComplete that would be fired as you can assume from its names when the filtering is been started or completed. Aside from showing a WaitCursor you could also use the property ItemsMatchedCount to check how many items are left after filtering.