Giovanni Campagna. a GNOME student developer, shared on Google+ a photograph with the caption of "Wayland is one step closer!" The blurry photo shows the GNOME Display Settings from the GNOME Control Center running on Wayland with detecting an internal LVDS panel on a ThinkPad laptop and an external LCD display.
Giovanni Campagna has been porting the GNOME Display Settings support to using the new Mutter Dbus API for display configuration. As part of the GNOME Wayland enablement, display configuration is now being done for GNOME via Dbus as with Wayland there is no "RandR" (Resize and Rotate) extension from X.Org. Patches for this work have been coming over the summer and now it appears working.
This new DBus interface for GNOME display configuration is modeled around the X.Org RandR extension but in a simplified form. A description of this Mutter Dbus interface work can be found here.