Legit Reviews posted an article about DDR3 and what it might mean for you.
With upcoming 333MHz FSB processors running DDR3 memory modules at 1333MHz will be a standard setting in the BIOS. To hit 1600MHz a FSB of 400MHz needs to be reached, but that is not tough to do as it would be a mild overclock. DDR2 memory modules on the market right now have been topping off around ~1320MHz, so DDR3 is starting off at the upper limits of where DDR2 starts to become unstable...Getting To Know DDR3 Memory Modules
