Previous reports on the Google cluster were pretty glossy - but now there's a detailed look at the cluster in IEEE Micro. The most impressive thing about the article is the level of detail of the optimization work done on the Google cluster. This is true engineering. Everything is measured and accounted for. No feature of the system is unanalyzed - from overall architecture and systems management automation down to consideration of what type of microprocessor kernel offers the best price/performance for search.
And the impressive thing is of course what is in the headline: All of this work goes into making the service as simple and fast as possible. In a truly golden performance, effort shouldn't show at all.