Two interesting blog posts (the second being an analysis of the first) about Google results' supposedly diminishing quality.

Dishwashers, and How Google Eats Its Own Tail, by Paul Kedrosky:
http://paul.kedrosky.com/archives/2009/12/dishwashers_dem.html
"It hearkens back to the dark days of 1999, before Google arrived, when search had become largely useless, with results completely overwhelmed by spam and info-clutter."

Anatomy of a bad search result, by Chris Dixon:
http://cdixon.org/2009/12/19/anatomy-of-a-bad-search-result/
"When you have a multibillion dollar economy built around keywords and links, the ultimate “products” optimize for just that: keywords and links. The incentive to create quality content diminishes."