Apparently the D90 was the best-selling dSLR in Japan for the first 6 months of 2010:
http://translate.google.com/translat...ml&sl=ja&tl=en
I'm pretty impressed by that seeing how it's an older camera compared to all the new fancy Canons.
Unless you absolutely need weather-sealing, a tougher metal body, and faster AF-system, I see no point in getting the D300s when you can get the majority of the features in the D90 (including picture quality).
Glass > body. Spend more on good lenses.