It is very likely that Apple has recycled the 5 Mp back illuminated CMOS image sensor from the iPhone 4. [sic] That unit was the Omnivision OV5650. The OV5650 is the second generation back illumination (BSI) technology from OmniVision. This 5 Mp camera features 1.75 µm pixels, and is designed to deliver DSC quality in a mobile phone application.
Follow the link for close-up photos and die image for the object(s) in question. (via iFixit)