Show information about touch gestures
There's currently no way to know touch and touchpad gestures exist if you don't follow GNOME development or read the wiki pages. While we have information about keyboard shortcuts in apps, there's no such dialog for the shell, so I think initial setup is a good place to show the supported gestures (and maybe even the important keyboard shortcuts).
A page in initial setup with some small animations of the touch gestures would be great (depending on the available input devices of course).