Any 28/50 shooter will upgrade their 28 Summicron to 28 Summilux?
http://leicarumors.com/2015/05/21/leica-summilux-m-28mm-f1-4-asph-lens-officially-announced.aspx/
http://leicarumors.com/2015/05/21/leica-summilux-m-28mm-f1-4-asph-lens-officially-announced.aspx/