Nikon has released updated firmware for the D200 (last week), D2Hs, and D2x (today).
The D200 upgrade only adds two features stated outright, compatibility with the WT-3 wireless transmitter, and Image Authentication support.
The D2Hs and D2X upgrades add a number of features from the D2Xs. These are extremely extensive updates.
I updated my D2Hs and D200 without a hitch.
Downloads can be found on your regional distributor's website.