From my perspective as a D1 owner (same resolution as the D1h) I'd agree with the other comments here. My typical print size is about 10.5 x 7 inches on A4 paper and at that size the prints will withstand close inspection pretty well.
I have also done some 17.5 x 11.75 inch prints on A3+ paper, but these are rather more variable in quality. A finely detailed landscape looks rather like a watercolour painting when inspected up close - there's no pixelization, but the details are soft. On the other hand close-ups of wildlife or flowers and portraits tend to look quite acceptable.
RAW mode makes enough difference in terms of the amount of detail visible to be worthwhile if you're going to make large prints. It also gives you much more flexibility when processing the image since you have access to the cameras full 12-bit dynamic range.