Hi Colin,
TabbedControlSelector is the MEF component that implements that functionality of letting the user press ctrl+tab and shift+ctrl+tab to switch between tabbed panels in a group of panels. Just drop it into your TypeCatalog. Many of our sample apps use it.
TabbedControlSelector switches between panels in the currently active docked (not floating) group of panels. It could use some improvements, like working with a floating group of panels, or maybe having the option of working just with documents. It lists other available dock groups, but doesn't let you select them. Also, the dialog box it uses, TabbedControlSelectorDialog, can't be customized currently. If you find you need to make modifications, maybe you can do so in a way that benefits others. But hopefully it's good enough for a first-pass.
--Ron