Sure - just like the iPad isn't going to kill off the Kindle overnight. Still, when a competitor can put out a product that halves your market share in its first week on the market, you sit up and take notice.

Everything Google's done in the last few years has seemed bent on extending their search ads monopoly to mobile devices. If success was counted based on devices shipped, Android was doing pretty well. iAd is a serious setback if it turns out to be more profitable than mobile browser ads.

Again what prevent Google from offering those types of interactive ads on webapps with HTML5 and js? you can still get creative with ads, and no one halved anyones market today.