As m1stake pointed out, DDR3 currently offers very little improvement over DDR2. In addition, prices are roughly four times higher for DDR3 RAM compared to DDR2 on Crucial's website. It's easy to pop 4GB into your MacBook for $100, but for $400?![]()
Like I said, DDR3 will provide some improvement. I never said it would double your processing power, nor did I comment on price.