For once I would have to say, "believe the hype". It's a camera that has totally changed the way I can go about photography - the high ISO performance means I more or less shoot manual constantly. I set the shutter/aperture combination I want, then leave auto-ISO to sort out the exposure. Focussing performance and metering are also very impressive.
As an example, my wife and I were in Barcelona recently in the Santa Maria del Mar church. I was looking around taking in the church, and a girl, absolutely lost in thought, wandered up to the candles, lit one, then slowly lifted the match up and blew it out. I had time to grab my camera (which was set on 1/60th and F2.8 I think) and snap a photo - ISO3200, but I was amazed how well it came out. It was close to dark in the church, but the D3 not only grabbed a very usable shot, but auto-focussed in an instant.
Same thing going to circuit Catalunya - I could set the shutter/aperture I wanted, then leave the Auto-ISO to take care of the exposure. The 9fps also helps when you're shooting at very low shutter speeds and trying to nail that one really sharp photo
(Much larger version can be seen on flickr)
Price-wise it's surely not for everyone, and I'm pretty sure that 99% of the performance will be available at less than half the price within a year or so. But....as icecavern said, it really is awesome!