If I had a D700, i probably wouldnt upgrade either, but im still at the D2x, and that camera is definitely holding me back. For macro it's fine, i could use it for 5 more years for macro, but for wide angle, this camera has cost me many shots. For instance, during our Sperm Whale trip last year, I was continuously working with a shutter speed below my safety margin because I did not want to go above ISO 400. That really sucked. I hadn't upgraded before because I thought the D800 would arrive a year earlier than it did. I regret not upgrading to the D700 3 years ago. I started this thread because I think more Nikon shooters are currently thinking along the same lines.
As for DX/FX, to me that discussion isnt so important. Sure, there are things to consider, but to me those aren't as important. I will consider any camera, regardless on if they're DX or FX. Im just naming the D7000 and the D800 because the D800 seems imminent (D700 is out of stock in many places, not to be restocked). I did not name the D400 because there seem to be a few uncertainties about it. I might switch out my D7000 for a D400 if and when it arrives. I will not consider a D4. Ive concluded for myself that even though I love the form factor of the pro bodies, their capabilities are not such that I see much added value above a D400/D800 style camera. Especially for underwater use. Actually, I see more negatives than positives.
Been shooting a bit more with the D7000, and haven't really noticed much that would annoy me. The only thing that could theoretically annoy me at some point is the low buffer. At my current settings im at a 9 RAW image buffer (my D2x sits at 18). Im not sure id reach that limit. The SD card is also a bit slower than my latest CF cards. I havent been able to do some serious 3D tracking yet, so cant say if that's really a problem with this camera. Probably not an issue underwater in any case.