I got a chance to play with an upgraded M8 with the new shutter. I shot it side by side with both a stock M8 and an M7 to gauge the difference in sound.
The M7 is still more quiet, but the new M8 shutter cuts the sound significantly. Also, when you press the shutter release, you can feel less vibration in the camera as well. When fired at me from six feet away, I couldn't hear the new M8 over the background noise of the trade show floor. I could hear the current M8 shutter, though.
Is it worth 1200 Euros? That will ultimately be up to the individual user. 1/4000 vs. 1/8000 is not a big deal. 1/180 flash sync vs. 1/250 isn't that big a deal either.
As far as new M8 cameras, dealers will have the option of offering the two different versions at different prices. No, I don't know the prices yet.
This approach to camera development is pretty revolutionary. Let's see how it all pans out.