New 18-200 zoom + D70s
Have a D70 & wife has D50. We just got 18-200mm. We reasoned same as in your post - we could have 2nd body and the lens for less than D200. We have been completely happy with the pictures from this lens on either body.
Don't get me wrong, I really like the D200, and want to get one someday, because IMHOP it is a truly professional level camera. However, I am willing to wait until startup problems like banding have been fixed and until I can place an order for one and realistically expect to receive it in the same week--which one cannot do right now. Meanwhile, we are happily taking pictures with D50 & D70, and the wife has pretty well taken over the 18-200mm lens.