Demand for DDR2 RAM isn't up to market expectations, but volume and availability has increased greatly over the past year. This is resulting in DDR2 losing value and the prices for it rapidly dropping, faster than DDR. From the article:
"DRAMeXchange indicated that spot prices for mainstream 256Mbit DDR 400 was more stable compared to DDR2 pricing, as memory makers have shifted their focus to 512Mbit DDR2 production. However, DRAMeXchange predicts that the price difference between 512Mbit DDR 400 and the same-density DDR2 533 will narrow after November."
This isn't necessarily a bad thing. Though initially it is a sign of low adoption that may make some manufacturers rethink their DDR2 production lines, it's a great thing for people like us. In the near future, a lot of people will be making the switch to dual core CPUs, whether with AMD or Intel. In just a few short months, we will have AMD-based motherboards that support DDR2 be commonplace in the market, and the prices for dual core CPUs on both sides of the fence is dropping. By the time DDR2 AMD boards are in full swing, the price of DDR2 will not only comparable, but perhaps better, than DDR. DDR still has a long ways to go – but eventually we won't have a choice. Unlike RAMBUS, I think, DDR-2 is here to stay for quite a while.