A new Ricoh GXR unit should land next year, and bring a large APS-C sensor to the modular camera.
Ricoh's Japanese site has supplied the barest bones of information about the next sensor/lens combo for the modular GXR. Set to launch in Japan in early 2012, it has a large APS-C sensor, will shoot 16-megapixel stills, and have a 24-85mm equivalent lens. This is the first APS-C sensor unit for the camera that has a zoom lens, though there were two primes previously released, a 28mm and 50mm.