Got long-waited D90 in hand yesterday (Saturday, Sep 6)! From Wolf Camera. Then got 4 in stock.
Actually I should have it on Friday with over-night shipping, but they sent it as 2nd air... :-(
Anyway, so far so cool! Will post some photos later!

Update 1:
Apple's Aperture 2.1.1 doesn't support D90 yet... Thus have difficulties to do post processing... Filed a bug to Apple already.