The Leica Super-APO-Summicron-SL 21mm f/2 ASPH lens should be officially announced soon – the lens product listing has already started to show up in Google search results:
The lens price will be €5,300 (around $5,600) and the minimum focusing distance is 21cm.
I could not access the listing from the US – if you are located in Europe, you may have a better chance of doing so – please post in the comments section if successful. Thanks!