I have the opposite preference base ISO DR is more important to me than High ISO noise
Marc
To put this in context, the SNR is always better at base ISO speed than at higher speeds; this approach of more early amplification of the signal at higher ISO speeds is just a way to reduce the SNR disadvantage in higher speed shooting. That is, it is more or less independent of anything that Canon could also be doing to improve SNR at low speeds.
On that latter goal, I see only two likely scenarios:
1. The two new Canon 35mm format bodies offer better pixel level SNR at base ISO speed (so called dynamic range) than what Sony and Nikon have been offering in 24MP sensors for several years, and better than with D800 output down-sampled to match the Canon bodies for resolution.
2. Canon has fallen fundamentally behind its main competition in sensor technology for still photography with decent light levels, and the only way to overcome that is something akin to the Sony approach of doing ADC on-chip, closer to to the sensel and probably with more ADC units to allow each ADC to operate at a lower rate.
In case 2, it is possible I suppose that Canon simply does not prioritize extremes of dynamic range, which are only visible when the image is displayed with a heavy artificial reduction of the brightness range between shadows and highlights. This could be because Canon has decided that using multiple frames and HDR is an adequate solution for those situations, or because Canon has decided that there is better ROI to be had from putting R&D resources into being the leader in DSLR video performance.