ExtremeTech reports: "DDR3 memory has arrived on the scene, but the move to DDR3 memory is looking a lot like the transition from DDR SDRAM to DDR2. What's happening is that newer memory trades off latency for bandwidth. ... The recent release of the Intel P35 and G35 chipsets is the beginning of the shift to DDR3, a new memory technology that builds on the foundation built by DDR2."
Do you want DDR3 memory, then you might want to check out this article before you buy it.