About the old Noctilux, some people said that it is just a f/1.2-lens anyway, because of the light falloff to the edges it was just f/1 in the inner center. This one has same 62mm filter diameter (Canon had 72mm) which looks to me that in the decision between ghost pictures/flare against light falloff, Leica decided again for the light falloff, whereas Canon did the opposite in 1961, and, if we users of the Canon dream lens all know, ghost pictures can be annoying sometimes...
As for the decision not to call it a f/0.9 just to heel Canon, my respects to Leica...
On the other hand, with the same lens diameter, it's obvious that it can't be much faster than the old Noctilux... so probably there is a limit which can't be crossed at reasonable costs even with the technical sources of 2008.
About the price of the Noctilux, I suggest this is the price of the "best of the best" in a small series, in 2008. The dream lens price was the price of the "best of the best" at Japanese wages in 1961, in a big production run. If they had to build it now, the price wouldn't differ too much from the Noctilux!