If they can reach such a price point, or let's say 10.000 US$, then this camera will indeed probably be a hit... my guess is that it will be at least twice as expensive though.
Besides, it all really boils down to what Nikon and Canon have up their sleeves. If Nikon indeed decided to go the MX route, then the Leica is IMHO going to have a really really hard time with the S2. I would think that starting from a white sheet of paper with less price constraint than they have ever had before, Nikon lenses are going to be pretty amazing too...
Leica's owner has suggested "between 10,000 and 20,000 euros" [how do you make the Euro symbol on a Mac keyboard?] and discussions on the Leica board seem to group around the idea of 15,000 euros -- but some people think that's a bit wishful. Given the cost of FF Leica lenses -- the new 50mm Nocti is $6,000 -- an S2 outfit with one lens will cost something north of $20,000, I suspect.
I agree that the Nikon project, if it comes to fruition, could be the end of the S2...but Nikon is being coy about this thing, like with its "BIG" ad in a wedding magazine, which makes me think it's possible that the MX might be some kind of very specialized and somewhat limited camera...Could it be a MF sensor with bigger pixels but fewer of them, for less resolution that other MF cameras, but better ISO response and maybe better DR, which is what you need in a wedding camera? How about 31 MP but the ISO response of a D3? We'll see, I guess.
Bernard -- you should be in good shape by the time the thing comes out, at 50 yen to the dollar/euro. 8-)