We've seen some very cool things with DDR2 the past few months. Just recently we saw Crucial unveil 1000MHz modules, and DDR2-667 modules with low timings, showing how much it has to offer. Without Athlon boards supporting it, though, it's pickup has been slower than expected. That's going to change according to manufacturers with the release of the M2 socket, AMD's next-gen "all-in-one" CPU holster. Early 2006, AMD will make the socket available and we will start seeing manufacturers release boards designed around it, including support for DDR2 memory. Nearly all of Intel's new designs already incorporate DDR2, so unlike the RAM wars of RAMBUS vs DDR we will likely see a unified approach throughout the next few years.
As a lot of enthusiasts start to pick up on the M2 and AMD fans follow with upgrades, DDR2 is expected to become much more popular fairly quickly. With the very high memory bandwidth potential of the Athlon64, DDR2 may be able to really shine with its high clock speeds. And we'll be able to find out in just a few months.