You miss understand basics.
All this CPU/Gpu combo is doing is displaying images in 4k res . Its not actually drawing games at 4k resolutions.
1080p is 2,073,600 pixels. 4k is 9,437,184.
This is roughly a 4.5 times increase in pixels. So your only looking at needing hardware roughly 4 times faster to draw the same image at the higher resolution . Your also going to need an increase in ram to hold the frame buffer too .
I'm playing games at 5760x1080p which is 6,220,800 on my pc and some people are playing even higher resolutions like 7680x 1440 which is 11,059,200 . So people are already playing beyond the 4k resolution .
THe reason why we wont see 4k next gen consoles is because there are no displays for 4k currently and we wont see them at any kind of market penetration till some time next decade.
Next gen consoles are due 2012/13 . Even if a 4k tv was released then , it would take years for it to reach enough market penetration for it to matter.
This gen is 720p and under . 1280x720 = 921,600 . 1080p as said is 2,073,600 . So we will already see next gen consoles needing to absorb a 2.25 increase in pixels , to go to 4k they will have to absorb a 10 times increase in pixel density .
So in many key area's a next gen console would have to be 10 times more powerful just to display a simlar experiance as todays games. Its just not going to happen