It is the
Kodak KAF-31600, 33x44mm, same pixel size as in the 39MP, 37x49mm KAF-39000, but with microlenses which about double usable ISO speed.
So, same sensor as in the H3D-31, but probably priced more like Mamiya ZD or even less.
I can see this possibly restoring the place of Pentax "645" in wedding photography.
P. S. After reading Michael's latest post on the Mamiya ZD, I have to say that at least Pentax got the LCD size right. With up to 3" LCD's in "pocket cams", and 2.5" now standard in even the smallest DSLR formats, it is strange that MF offers anything less; especially less than 2" as in the ZD.
For comparison, about 2.7" diagonal LCD would match the image size on the ground glass of 645 format, and 3" about matches the image size on the ground glass in 6x6 format. Given that many people have worked successfully with the top down viewing of the image on the ground glass of a traditional MF viewfinder, a 3" LCD could be at least equally useful for preview and review once the resolution is high enough (which it is not yet, arguably, until one zooms the LCD image).