You already know this, but here's the obligatory link to a discussion of Google's earnings coming in significantly higher than expected, jump in price, etc.
Here's a nice post dissecting some of the issues: Google's exerting more buyer power over AdSense, cutting revenue shares to smaller partners, and AdSense is responsible for about half of revenues and has the same growth rate as search. Which is possibly the strongest validation for massively distributed media models one could ask for.