It seems to be that the firmware 1.0 for Pentax K10D is finally out. Japanese website Impress Watch have a short review of K10D + DA 16-45 F4 lens with a lot of full size samples (translated by Google). Look at the EXIF – software ver. 1.0.
Noise is a hard to spot up to ISO 400. You should look very close to spot any deviation from perfection. ISO 800 is pretty usable too. And the ISO 1600 is much better than Sony A100 which is based on the same sensor.
Some other samples shows excellent dynamic range (thanks to 22-bit A/D converter) with the plenty of details and exceptional sharpness in lights and shadows.