6400 ISO

This is a 6400 ISO picture from the Nikon D700. Goddamn!
That shows the advantage of the light-gathering power of a large sensor. This is about as good as you'll get from a pocket camera at 400 ISO. That's a four-stop difference.
(In good light it's another thing, you can get amazing quality from a pocket camera at low ISO settings.)

I was hoping Canon would match the D700 performance with their upcoming 5D replacement (seemingly called 9D), but apparently they chose to instead up the resolution to 16MP and limit the ISO to 3200. A pity.

Update: It's odd, though, Cameralabs are getting more noisy results.