Like many others, I'd been waiting anxiously for the D700 replacement for a LONG time. It never came. Instead of taking Canon's approach of making smaller, evolutionary changes to their product lineup, Nikon has chosen to take a revolutionary step up. The thing is, when I examine my needs (how I shoot, and what I shoot for) I don't really need the D800 now.
To me, the D800 is more like a medium format camera in a smaller, lighter sized body. I would have to employ medium format techniques and the best lenses to maximize the potential of the D800. That means I would have to slow everything down, maybe use a tripod, and use heavier, 'professional' lenses. It's also a touch slow at 4 frames-per-second out of the box. There's a DX mode, which looks useful for someone transitioning out of their cropped Nikon bodies, but it's not a reason why someone buys this camera.
The D800 would really suit a variety of commercial photographers: like wedding, portrait, product or nature; where the subject isn't very active, and the end result requires very high resolution with a very high dynamic range. For travel and adventure, I need a camera that is more versatile. My D7000 is lighter, shoots at a higher frame rate out of the box, and gives me more than enough resolution for stock photography and magazine prints.