I am a happy owner of a D80 which served me well for almost two years now. After I bought it I regretted a bit. I thought I would have missed the faster continuous shooting mode of the D200 (which I eventually did) and the tropical sealing. Thus, the D80 survived the most severe environment you can think of, a boat in the middle of an ocean, many times per year, for many days in a row. No, I cannot complain about my low budget purchase, with the money I saved at the moment I bought myself the 18-200VR (the lazy man lens), a nice 35mm f2 and other gimmicks. Well, truth to be said, overall they costed me more than the difference between the D200 and the D80 but we know how these things work.
Now the D90 hits the market. Looks like it will be some 600€ cheaper than the D300 (at least in Europe) and still offers some very good technical specifications. If you like to read a preview see what the guys at Digital Photography Review (a very serious web) have to say about it http://www.dpreview.com/previews/nikond90/ . My only worry at the moment is that once again I will have to think whether to fly low and save money or finally go for the better machine hoping that the expense will pay itself in the long run. You are right, is not a big deal of money and eventually I kind of "work" with the camera, she brings some money home too, but since is not the camera that takes the picture and that you don't need a great camera to take good photos, wouldn't be a cheaper and more humble D90 be enough for a humble photographer like myself?