I nearly purchased a D2X but decided not to for now. I'll tell you all the issues I kept thinking about in my decision.
I bought a D2H maybe 6 months before the D2X was released. I feel I was really burned on that because I paid $3,200 for it, then Nikon released not only the D2X but also dropped the D2H and released the D2Hs! This act severely depreciated my investment, and left me with no upgrade path other than to eat the huge loss, a much bigger loss if I were to then purchase the D2X for another $5,000, and sell my D2H for nothing near what I paid for it.
The price of a D2X will likely drop with the release of a D200, which itself will cost considerably less than the D2X now. From all the ramblings I hear, the D200 will probably be the ideal camera for many of those who are buying the D2X now, only because there is no other comparable model to choose from. If you still want a D2X later, I would expect more used models to end up for sale by that time as well, and it still won't be an old camera. Already I'm seeing the price down to $4,500 with some vendors.
If you have all those MP of the D2X, what kind of computing equipment do you have? It will take a significantly more powerful CPU, hard drive space and RAM in your computer to work with files that are so much larger with more detail. Photoshop and other editing programs will eat up much more system resources in the editing phase. If you only work with the JPGs to get around this issue, then you've just purchased a high resolution camera to output files similar to any other camera you might be using now. I know many people will disagree with me on that, but if you dont have the computing power to work with the RAW NEF's it produces, then what's the point really?
All first issues seem to have problems. The D2H has the light meter issue that will almost certainly happen to every D2H at some point in time. Right now the D2X has it's focusing issues. Nikon is making D2X repairs a priority, but its not an uncommon problem. The D70 has its GBLOD, becoming more and more well known. If the D200 does have it's own problems, at least we can expect it shoudln't inherit any of these known issues from other models with similar circuitry.
If you don't mind spending the money for a D2X now, knowing a D200 could be everything you need in the D2X at a much reduced price, then by all means buy it. But you should realize you will probably lose a significant amount of your financial investment after the release of the D200. People that have a true need for the D2X and its MP now, who are earning a significant living from their photography should not wait. But that's the only reason I can see for doing it, if you already have something that is working for you right now.