The difference won't be that big, but you it'll be a bit faster than DDR2 and a lot faster than DDR, but inverting money on it atm is kinda stupid since isn't even out yet, and by the time it's out there will be better mother boards/processors/video cards which will make a better usage of it
I think DDR3 would be a little far out into the future at this point, I will certainly not be holding out for it to come out before upgrading.
[-0MEGA-];682906 said:DDR3 will be exactly like DDR2 was when it first came out.
It will have high clock speeds, but high latency as well, so the low-latency DDR2 will perform roughly the same until DDR3 can create faster, and lower timings on their RAM.
Also DDR3 is going to be $400+ for a 2GB set, while DDR2 you can get for $70+.