I read something that I thought was interesting. Rumor has it that Canon's upcoming 120 megapixel DSLR might have a five layer sensor, similar to Sigma's three layer Foveon sensor. It's not unbelievable because Canon holds a patent for a multi layered sensor. In fact, they already have a two layer sensor in which one layer is used to record the photograph and the other for auto focus.
Sigma's sensor has one layer sensitive to each color channel (one for red, one for green and one for blue). This has some significant advantages over a traditional Bayer sensor, especially for black and white photography. But Sigma, with a more limited budget and resources than Canon, had a hard time getting past the disadvantages (slow software, poor high ISO performance).
It's not been announced what the five layers will be on Canon's new sensor, but we can safely guess that a layer will be dedicated each to red, green and blue sensitivity. Rumor also has it that one layer will be sensitive to infrared. Most cameras have a infrared filter, but, with a sensor layer instead of a filter, I'd assume that you could do infrared photography with the push of a button. Just guessing, the final layer would be for auto focus.
It will be interesting to see if each layer has the same resolution like Sigma's Merrill cameras, or if the layers will have different megapixel counts, like Sigma's Quattro cameras. If all five layers are the same they will have 24 megapixels each. However it is divided up, the camera won't have 120 megapixel resolution, but perhaps something in the range of 60-80 megapixel equivalent. That is still tons of resolution, and more than most photographers will ever need.
If the camera works well and if Canon can overcome the shortcomings that Sigma couldn't, this camera could be a game changer, assuming that the price isn't too ridiculous. It would likely spell the end of Sigma's camera brand, and it might leave Sony scrambling to develop their own multi layered sensors. Some brand might just buy the Foveon technology from Sigma.
If the camera flops, this might spell trouble for Canon, who is seeing sales spiral downward. If sales are slow for this camera, with all of the time and money that they have obviously invested in this new sensor, that might be the straw that breaks Canon's back.
However it goes, it will at the very least be interesting.