HTC needs a best-selling phone and the HTC M7 just might be it. Rumor has it it won't use a 13MP camera like the current cream of the crop, but a new design with so-called ultrapixels. It sounds very similar to the Foveon X3 (http://en.wikipedia.org/wiki/Foveon_X3) sensors by Sigma.
Traditional sensors use a Bayer filter (http://en.wikipedia.org/wiki/Bayer_filter), so each pixels captures only a single color. This means a 13MP photo shot with a traditional sensor has 6.5 million green pixels and 3.25 million of red and blue each. The final image has three colors per pixels, but the missing values are interpolated (math is used to calculate their approximate values).
The HTC M7 sensor will have three layers of pixels stacked on top of each other, each layer capturing one of the three primary colors. Each of the three layers has 4.3 million pixels. So, each ultrapixel will combine real readings from the three layers.
This is somewhat similar to what Nokia did with PureView Phase 1 (the Nokia 808) - the sensor there still uses a Bayer matrix, but thanks to the huge resolution of the sensor, each pixel in the final image is the result of