On related news, according to this article at The Inq, the GeForce 6800 Ultra will remain clocked at 400MHz and no "Extreme" version of the chip is on their plans. Product partners may release special overclocked version of the boards, using water-cooling for example, if they wish.
Last but not least, and of more relevance to us... Nvidia has lowered GeForce 6800 Ultra's power supply spec. You may recall from the product launch that the graphics giant recommended 480w PSUs to review their cards (which is non sense IMO!), apparently they are once again correcting themselves and have been able to lower requirements so that less-expensive 350W PSUs will be able to handle the load.