Bodies come and go (and stay on sale for four years). I see a new body release as a perfect opportunity to get a good deal on the previous generation or gently used glass, both of which flood the used market as people scramble to budget for the new model.
I was actually looking to buy an f/1 Noctilux, and found that the f/0.95 is readily available for not too much more, no doubt from people selling them to fully fund an M10.
Its clean at 3200. 6400 probably, but not in every shot and not with proper exposure. Banding rarely shows up in the way I use high-ISO on any camera as I tend to prefer my night shots to look like night. Instead of using high ISO to create day from night, I use it sparingly, and let the darkness stay dark. I never went above 6400 on my 5D3 with a 50/1.2 lens, and very, very rarely even hit 3200. The M-D is at least as good at high ISO as the 5D3 was.
Where I see the biggest improvement from the M-E is at ISO 1600, where the M-E started to fall apart the M-D still looks terrific, equal to ISO 640 on the M-E.