Comming soon next months, New sensor Sony 12/13Mp New more powerful controller and integration of D-Lighting (Sic!) New AF 11 collimators CAN BE derived from that of D2x Better treatment of the noise, exploitale until 1600ISO, even 3200... Even frame than D200. look much more a new definition of D200 X than a new D300. Now if the sales strat very well for this camera you can expect less prices for others materials like D200 - D80 etc...
i start with a Olympus probably 12/14 Years, afther this one i bought a Canon great material but i need something different so i decide this month to do the step for a Nikon, the material i dream since so many years. keep it! D50 it s great material, so wait the release of the new one, the prices going to descrease faster. it give s you the time to make your decision for the material you need.