I got the opportunity to take a look at one. It's.......completely amazing. As good, if not better than the D300. Actually, Nikon has had the chance to refine, refine, and refine some more each new sensor. Even though the D90 and D300 sensor are the same as far as being CMOS and same dimensions, I think the picture quality about the same. I shot at 6,400 equivalent on the D90 and only viewing the picture on the camera, I could see VERY minimal noise at all. If there was ANY, it was mainly in the shadows which is mainly where noise shows up.
For the most part, I am very please with it's high ISO capabilities. Too bad it's not the D300 though.
~Michael~