What Panasonic proposes, like Nikon, probably requires changes to the stepper process in fab. Doing anything beyond lithography is technically challenging, and it doesn’t always work out in production the way you think (you can get low yields, for example).

In Japan, one of the speculations in the business press is that Panasonic wants to unload their sensor business. Puts a slightly different spin on why they might want to out an interesting new technology, doesn’t it?

Artifacts show up in different ways in transforms. As Esa points out the usual problem is that you end up with noise in the color channels. Remember, noise is the thing we’re trying to avoid by removing the Bayer filters, but we’re adding it back in via another method. That’s one reason why I wrote “partial breakthrough”: the implied gain was one stop (actually 0.85 stop IIRC from the original Panasonic documents), the actual gain will be less than that. Gains are gains, sure, but as Sony has proven with the EXMORs, reducing read noise brought a big bang for the buck, and has no downside. We used to have DSLR cameras with read noise in the 10 e- range. Now we have one that’s 1.4 e-. The signal to noise ratio is generally stated as saturation minus read noise. The smaller the sensor is, the lower the saturation number is, making it more important to lower read noise. But if you then add in a new computational noise, you don’t make a gain.