GR Digital V has an APS-C sensor

If Ricoh is able to make use of X100-style microlenses tuned to their chosen fixed lens, then this camera could easily end up a good deal smaller than the GXR/28mm combination. The GXR (and previous GRD) lenses are built around the idea of telecentricity being necessary for good wide-angle performance on a digital sensor - hence their nozzlecam extending lenses. One would hope that with the GR line's reputation for small size, Ricoh will be at least as ingenious as Fujifilm at making their flagship camera compact in all ways possible, including positioning the lens deep inside the body.