Unlike the past when both the manufacturer and AIBs shook their heads at any form of manipulation with voltage on graphics cards to favour a better overclock, these days it's a different story with some companies going so far as to provide software with their cards that promote the ability to do so for your overclocking pleasures.
With that said, our VGA man Shane Baxtor has learned that NVIDIA won't be cutting overclocking hungry folks out with their latest lineup of DX11 based cards to hit town, GTX 480 and 470. The company is apparently going to be happy in offering people more options when tinkering with their overclock result including the ability to adjust the core voltage via the card's PWM chip, within a respectable limit of course.
What we won't know until cards start to show up on the market is how the various AIBs will provide this ability; whether it's via a unique piece of software that lets the user tap into the voltage levels, or a standard feature directly from NVIDIA themselves.
Providing this pertains to be true, we could be seeing some very serious aftermarket models coming out once the initial rush settles down that house more powerful coolers which in turn give the ability to push those voltage levels even higher whilst keeping the extra heat at bay.