I was simply running and gunning around my condo in very dim lighting this evening, and I am continually amazed at the sharpness, the clarity, and the beautiful colors that come out of the D3. Granted, pairing it with the amazing Nikon 50mm f/1.4 is much akin to pairing cream and a doughnut... but still:
ISO 3200, extremely dim lighting, Nikkor 50mm f/1.4 @ 1.4, 1/40 second exposure (!)
I tried the same picture with the D90, and not only could I not get critical focus (it was hard to get it to focus on the central chain without guessing and moving forward/backward between shots), but even when I was close, there was nowhere near the sharpness or clarity afforded by the D3's FX-size sensor.
I have one word for the D3: want.