Pentax Japan has posted five samples from their 645D medium-format DSLR. The samples are available to view and download at the Pentax Japan website.
For now, the 645D is only available in Japan. It features about 40 megapixels on a 44x33mm image sensor. It uses a 77-segment multi-pattern metering system and can shoot up to 13 fps.
The Pentax 645 system dates back to 1984, when Pentax released the world's first multi-mode medium format film camera. The Pentax 645 incorporated the most advanced SLR technology with a compact design. It offered multiple exposure modes and featured electronic push-button controls. The manual focus Pentax 645 was replaced by the autofocus Pentax 645N in 1997 and later by the Pentax 645NII. Over the years many dedicated, interchangeable lenses were produced for the 645 system by Pentax and other companies.
(via Photography Blog via RiceHigh's Pentax Blog)