That's a very good question....
I do think one has to consider lens selection to get the most from the FX format. When I bought the D3 six months ago with the 24-70 f2.8, I thought I would be satisfied. I then realised that my 12-24 f4 DX didn't quite cut it and the 70-200 f2.8 VR needed more reach. I also never reached for the D200/17-55 f2.8 or the 12-24 f4...so I sold them.
Then I decided to buy the 14-24 f2.8 and 300 f2.8 VR to fill the gaps.
So.....seriously consider the total cost if you plan to go with FX format.......but, it's sooo worth it.
28-70, 80-200 AF-S (maybe replace with a 70-200VR), and 50mm 1.8 (probably upgrade to 1.4 eventually). The only thing that worries me is I've gotten so used to the DX reach that 200mm just won't feel like enough reach sometimes. I may spring for a 300 F4 6 months after the D700.
I only have two DX lenses which I'll be selling anyway and likely get a Nikkor 16/2.8 fisheye. All my other lens purchases have been made with the FX (well, film frame) in mind.
My 28-70/2.8 is practically like new in box since I have only been using it with my film cameras... and not often. The focal lenght just never made no sense in DX. Tables will turn now because on DX my main lens was the 17-35/2.8 and that one will be too wide for general use.
Wish Nikon made a 75-150 AFS f/2.8. That would be a sweet portrait lens for the FX format, perhaps add some DC. A 135 f/2 AFS would be a nice alternative.
I'll keep my 17-55 for the DX format. Probably keep my 10.5 DX, as well. I'll marry the 70-200 to a D300 body. So, when I walk around, I'll have a 14-24 on a D700, 17-55 on a D300 and 70-200 on a D300 and hope nobody robs me. That will give me a 14-300 range at 2.8.
I'll probably have to replace my 17-55, 50-150 and 12-24.
For as much as I use the 12-24 I'll probably get a used 17-35. I may have a line on one already, a freind and some times second shooter, just went to Canon. I might be able to work out a trade for services.
The other two will end up going for the 24-70 and 70-200. Although I might look at the Sigma 70-200. I've been happy with the 50-150. We'll have to see.
I might just do the 17-35 and 70-200. I'll end up keeping the the Fuji more than likely and I can fill the gap from 35-70 others lenses (I have the 28-105 and access to a 24-120). The D700 will be the wide or across the room available light camera anyway (which leads more to the Nikon 70-200 VR). I was hoping for a new version of that so the current version used prices would drop a bit.
Well the D700 sparks my interest and my get me back into the never ending sinkhole of buying camera equipment again. If I pick one up I will be using my 17-35mm that has been with me from the film days. My other lenses are DX, so I'm looking at picking up the 24-70mm or the older 28-70mm.
First lens going on it will be 24-70 f/2.8, followed by 70-200 VR. Will try out my 50mm AIS, and my cheapy 18-35mm (should replace it soon with a 14-24 f/2.8). In the near future, a TC-17E II and maybe a PC Nikkor.