Nikon D90 is now listed in the discontinued section of Nikon Japan website:
Nikon D90 was announced back in August 2008 and it was the first DSLR camera with video recording capabilities. The D90 is still the most popular camera on flickr and is still available for sale at all major online retailers. The D90 was replaced by the Nikon D7000 last year. This product line is on a 2 year replacement cycle and you can expect the next update to come in August of 2012, just on time for Photokina 2012.