I was relieved to see there will indeed be voltage regulation available on 6850 at launch. If you care to seek it out, pics of the box for the Asus voltage tweak version are out there.
For whomever asked, yes the pci-e connectors can carry more than their rated spec, but I highly doubt AMD would use 1 connector if overclocking at stock voltage would surpass 150W...That's just how they play the game.
960sp should be a sweet spot (ie pretty great perf/clock scaling) and AMD's TMUs are more efficient than nVIDIA's; 6850 should be a pretty impressive product.
It appears to have similar performance per clock to GTX 460 with one less power connector, and likely higher obtainable core and mem speeds considering AMD's past 40nm designs. After-all it will use 5Gbps memory according to most things I've seen, and AMD has undoubtedly a better memory controller than nVIDIA which can scale to that speed even with the lowered mem voltage on the past 50 products. Evergreen core designs hit 925-950 before requiring heavy voltage/massive power consumption, granted they were capable of 1ghz+, and I imagine this again will be similar. The '70' versions stock voltages already are at that sweet spot, and the default 6870 clock reflects that. I doubt there is much room left in it at stock. The 6850 though, I imagine performs similar to past '50' products (1.05v vs 1.15v on 70 products) and will clock to approx. 825-850 on stock volts and likely still be under the 150W of the spec considering 900mhz is only 151W.
Basically, I want to see a slightly v-adjusted 6850 @ 900+/~5000. When 6850 comes down in price (after 5800 series stock is cleared) to compete with the 460 768MB, I imagine they will be a pretty great deal.