Having 19580x12600 in a 29.2x20.2mm, great! Considering the wavelength of visible light, that's about twice the minimum theoretical size of a photosite, assuming perfect optics, of course. It might have applications for research where they sometimes use electronic microscopes to "see" things too small for regular light waves.
But of course, such a limited niche market is too small, so let's sell these chips to masses. So in 5-10 years, we will sell 100 Mpixels cell phones and 150 MPixels DSLRs. Now, I'll be able to send only 8 photos per month without busting my cell plan and my brand new 2 TB disk will be good for only 13 000 photos. Besides, I won't be able to send any photo by email, so I'll have to send them via FTP through my own site or pitch them somewhere on the cloud.