The upcoming Leica DG Nocticron 42.5mm f/1.2 ASPH MFT lens is a very big lens. Mobile01 leaked the first real image of this lens. When on Panasonic GX7, it looks so big.
This new lens will be available in 2014, and the price is not available yet.
Update: more images with GX7 from Digicame-info: