Fuji is very likely to launch a mirrorless system camera in 2012. And it’s also on of the few players (Unlike Olympus, Pentax or Nikon for example) that is producing their own sensors. So you might be interested to see what they are working on. The japanese blog Egami found a new patent (filed in 2009.9.29 and published 2011.4.14) that discloses a new three layer technology very similar to the current Foveon sensors from Sigma. As you probably know the single RGB pixels are arranged vertically one below another. Theoretically the advantages are:
1) no color artifacts
2) More of the photons entering the camera will be detected (larger pixels compared to Bayer sensor)
3) No need for demosaicing and the separate anti-aliasing filter commonly used to reduce the occurrence or severity of color moiré patterns. As a result we have a higher resolution.
Anyway keep in mind. There is a long way to go before a patent gets used inside real products!