I'm looking at the Canon EOS 1D Mark IV SLR Digital Camera at B&H and their specs say it'll shoot that high an ISO.
Given that my lowly XTi has a virtual meltdown at 1600 in anything less than daylight/outdoors/direct sunlight I have to wonder what such a high number would do in terms of grainy pictures.
What use whould it be to a photographer? Maybe cave shots for spelunkers?
Inquiring minds want to know (and maybe see a shot taken at that ISO.)