Would be interesting to see if there is a real (eg 1 stop?) improvement to the D3s' high ISO capability. Announcement claims that the sensor has been COMPLETELY redesigned:
"The D3S features a completely re-designed 12.1 effective megapixel image sensor. The large pixel pitch, with a completely modified inner structure, means that the D3S can capture images under light conditions which were previously believed to be impossible. The seven stop ISO range of 200 12,800 enables image and movie capture in extremely low ambient light conditions which is essential for todays news and sports photographers.
Further proof of the D3Ss incredible capacity for low light photography is the fact that it is the first camera to offer no less than three additional ISO boost levels, up to Hi-3, (ISO equivalent of an astounding 102,400)."
It seems too soon to expect a major leap in ISO performance...