An article in The Scientist provides a sense of how much DNA sequencing costs have fallen. At the bottom of that page they show 3 costs from 3 different sequencing instruments for doing a sequencing of the Drosophila fly genome. The established ABI 3730 has a sequencing cost for this job of $650,000. The 454 Life Sciences instrument costs $132,000 for the same job. Big cut in cost, right? But if you paid $132,000 you paid too much. Using the Solexa instrument costs $12,500 for the same job. Wow.
Apparently, Moore's Law of semiconductors (a doubling every 18 months) is slow compared to the speed of advances in DNA sequencing.