tem00: Sensor size has nothing to do with it. It's the technolgy in the sensor and the relationship with the lens. In years ahead, a 4x3mm sensor will most likely be resolving 12mp very well. Lenses designed to use it will give all the benefits you think you need in large sensors today.
Tem00: Your cousin with a PhD was "mistaken". Even Freshman Comp Sci majors know that Moore's law has been applicable since the seventies (transistor density doubling approx every two years, with concomitant performance increases - See Pollack's rule!)