I could try to regurgitate the info for you, but you'd best look firsthand at
Rob Galbraith DPI: D2Xs replaces D2X as Nikon's flagship digital SLR
If you can get a D2X at a lower price than a new D2Xs then go for it, since the latest firmware for the D2X adds
most of the "new" features that were implemented in the D2Xs... see
here for details