DDR2 has still not had its big break-through, which will probably come with AMD launching their Socket M2. The prices for DDR2 though, are sinking for each and every day, and obviosly in a rate faster than the DDR1-memories. The reason to this is that more memory manufacturers start focussing on the DDR2, which undoubtedly will take over next year. At the same time the DDR2-prices are higher than the DDR1, so there is of course more to cut off to lower the prices. The price differences between DDR1 and DDR2 will be much less after November according to DRAMeXchange.
Source: DigiTimes