that this sensor is NOT the same as used in 5DMK3 but it is totally NEW and that he was thinking that 6D sensor will be performing a bit and slightly better than even the 5DMK3 but this said in the low-light-situations when using high ISO.
They developed a "totally new
" sensor that manages to show " slightly better
" performance?! And ony in extreme conditions (high iso @low light) and with some loss of resolution? Great work, Canon :-p
Please note: newer is not always better, and overall it sounds as if Canon is mighty proud to have reduced costs while keeping the sensor performance on 5d3 level - after all they'll want a higher profit margin even after stuffing in wifi and gps with the 6d over the current 5d2 price.