From my trip, the first two are my favorites, and the last two show the sort of thing that convinced me to get the D7000:
Nikon D50/18-200VR @ 200mm, f5.6, 1/45sec. Pretty much the full frame, but heavy processing to adjust exposure and sharpen, as well as remove a lens artifact from the left rear wheel. Not much dynamic range required,
This one is about 50% of the original image:
D50/18-200mm @200mm, f5.6, 1/180sec, -.5EV. The heavy cropping starts to show the limits of the 6MP resolution. I sharpened this one heavily, and you can see the artifacts of that in the smokebox. Actually, I think it kinda makes the photo, gives it a gritty look. But I'd rather be able to choose to do such effects than to end up with them as a result of resolution limitations.
Here's one that shows what I'm after in dynamic range:
D50/18-200mm @82mm, f5.3, 1/90sec. I'd like to get more sky detail in such shots, without having to do layer gymnastics in post processing.
Now, here's a three-exposue HDR amalgam that I think I could get with one exposure from the D7000:
D50/18-200mm @18mm. +2/0/-2EV combined in Luminance HDR. With 5 exposures, I probably could have gotten more detail in the open door, but that would not have looked realistic, IMHO.
Back to the original topic: I'm a casual photographer, and I probably would do just fine with the D50 and the 18-200 zoom. But I figured (after a lot of investigation) there's a little more I wanted in a camera, and the D7000 deal made it do-able in the overall context of our financial priorities. Oh, and my wife likes deals, in a responsible sort of way...