Higher ISO, marketing game? or something to do?
So higher iso performance is just a matter of marketing game? or something to do?
The higher iso capability certainly give an overall improvement on photography options. Firstly, at the same exposure amount, a smaller aperture can be used, this ensures the DOF coverage for the subject in sharpness, it also means a higher shutter speed is possible to freeze actions.
Most lenses go to their sweet aperture after stopped down 1-2 stops, the higher iso sensitivity also makes the optimal setup easier. On the other hand, you may use lower speed lens, and thus less investment.
Check these samples at iso3200 that are very usable.

February 17th, 2008 at 7:20 pm
Have you seen the new Nikon D3?
Goes to ISO 25,600!!!
The ISO 6400 gives me the same results as my Fuji S5 at ISO 1600. staggering!