New battery regulations in Japan, along with the end of life cycle itself, have prompted Nikon to stop selling the D300s and D700 there, and these models have been moved to the Discontinued camera list on the Nikon Japan sites.
Given next week's big camera trade show in Japan, don't be surprised if new models get announced. Nikon isn't likely to leave a huge gap between the D7000 and D4 open for very long.