Yongnuo officially announced the F-mount version of their new YN 50mm f/1.4N E II lens. Additional information including technical specifications, MTF charts and lens design can be found at NikonRumors (Yongnuo products are sold at B&H and Amazon):
Update: the new lens is already listed for sale at eBay UK.
Yongnuo YN 50mm f/1.4N E II lens for Nikon F-mount officially announced
