This new lens, and the 50/0.95 upon which it's based, look like wonderful creations, and I echo what has been stated above: I'm glad that Leica designs and produces these type of lenses to show what is possible.
Having said that, I didn't replace my old 50/1 Noctilux with the more modern f/0.95 version, and I have no desire (from what I've seen so far) to replace my 75/1.4 Summilux with this 75mm Noctilux.
This is because I think the new lenses are too good, and I, like many others, prefer the somewhat softer, imperfect, rendition of the older lenses. I like that the older lenses exhibit different character wide open compared to stopped down 2-3 stops.