Tis weird how DDR2 hasn't necessarily been a big no-no when looking for a replacement 775 mobo. I kept DDR2 in mind with the last gaming mobo I picked out, merely cos I had some nice stuff already in mind. Extra cash on the mobo rather than a new batch of DDR3.
There isn't a big leap in every-day performance, or atleast enough for u to make a big deal out of it. Artificially the numbers are there. Indeed from the Intel 4 series, it's believed DDR2 compatibility holds the chipset back.
It would strike me as unusual that new customers to a mobo/memory would still look at a DDR2 system. And many of the existing DDR2 kits in use are very well warantied these days.
Interesting release. Be interesting if they bundle Futuremark stuff with DDR3 kits also.