Maybe this is just what you do when you've got a lock on 95% of your market, and you're massively profitable. Defensive maneuvers make more sense when you're executing flawlessly on the offensive front, and you've got resources to spare.
I'm inclined to take Eric Schmidt's blog post on this at face value, i.e. Google had a YouTube video with an overwhelmingly positive response and $20B cash in the bank, so they figured they might as well run it as a SuperBowl ad.
