There's some really good stuff in this thread. And after reading it, I've decided to add my two cents...
I've been shooting Nikon bodies since 1996. I'm sure others have been shooting much longer, and I definitely respect their perspectives. But this is my humble take on the subject.
I was extremely happy with the results from my film cameras. I shot the F3 and N90s mostly, but I also shot a few other bodies. I loved the darkroom experience and the magic created by the camera, film, and lenses I shot. When digital came out, I was reluctant to try it, but eventually caved in. I started with a D70, moved to a D200 and then a D300. I was very happy with these cameras and their renderings but there was something missing that I can't explain.
I bought an Epson R2400 when I had my D200 and began printing my shots. They weren't bad, but I was never happy with them the way I was happy with my film prints. I also didn't like the perspective of my lenses on DX bodies. Nevertheless, I plodded onward...to the D300. Not much difference in output between the D200/D300. I was blissfully ignorant of the possibilities of FX - until the D700 hit the market. So I bought one.
It was as if light came in like a flood - both literally and figuratively. My photos began to "pop" and my prints went from good to spectacular. I wasn't doing anything different, but my results were better. I can't explain it. Perhaps I became a better photographer; perhaps the stars aligned correctly and everything fell into place. I'm not sure of the reason, but I'm sure of the outcome: my photography improved.
Now the next generation of FX cameras have hit the market. While I'm certain that these cameras hold advantages over my antiquated D700, I think I'm gonna stick with what I know best. And I have no interest in upgrading my old printer either. The modest 12MP sensor of the D700 is quite enough for 5x7, 8x10, and 16x20" photos. So when all is said and done, I have to realize that chasing the latest and greatest isn't necessarily the wisest course of action for me. Instead, I'll try to learn more about a camera that exceeds my talent as a photographer.
But of course, that's just my opinion. I could be wrong...