There have been conflicting reports on the sensor used in the 645D. Originally it was announced as 18 megapixels and later 22. Some recent reports are saying 18 but I suspect they're just looking at old press releases: A check of Kodak's web site reveals that the 18 megapixel sensor isn't listed any more. Probably been discontinued as it didn't make a lot of sense to offer both the 18 and 22 megapixel sensors (unless there was a big cost difference between them, which probably wasn't the case).
We're likely looking at a 22 megapixel camera.
