The answer to that question is not as straightforward as it seems. Prestige is all-important in this sector and the likes of Corsair and OCZ have been slugging it out, releasing faster and faster modules in the last few months.
With CES 2007 drawing considerable attention from the media, having the fastest DRAM in early January is a significant boost for any company.
PC8000 is old hat, and PC8888 isn't on the bleeding edge of performance any more. PC10000 (1250MHz effective) is where DDR2 currently at.
Corsair has announced that it's unveiling TWIN2X2048-10000C5DF DOMINATOR memory at CES 2007, designed to run on NVIDIA's nForce 680i SLI chipset, and shipping kits will be available by the end of the month. You can read more here. We'll be taking a closer look at it very shortly.
Just how much headroom does DDR2 have and where will it end? PC11000, anyone?