A new Leica SL firmware update and the official release of the Leica Summilux-SL 50mm f/1.4 ASPH lens are rumored for early 2017 (the shipping date listed online is January 15th, 2017). Some low-res sample photos with the new 50mm SL lens can be found here and here.
The new Leica Summilux-SL 50mm f/1.4 ASPH lens is currently available for pre-order at:
Leica SL with the new 50mm Summilux lens compared to the Leica M9 with the 50mm Summilux ASPH lens:
Additional pictures of the Leica Summilux-SL 50mm f/1.4 ASPH lens: