The OpenWFD back-end is being removed that implemented the OpenWF 1.0 Display specification, which is a Khronos Group specification for governoring the display control hardware with mode-setting on displays, display discovery, direct pipeline control, and other functionality in a standardized way. OpenWF was released in 2009, but hasn't seen too much widespread adoption.
The OpenWF Working Group did offer help to Wayland developers, but this back-end is now being removed over lack of maintenance. There aren't any upstream developers working on the OpenWF support in months.
Dropping OpenWFD was brought up on the wayland-devel list earlier today.