iAd is probably a more controversial announcement. Apple hasn't traditionally been an advertising company until the recent acquisition of Quattro Wireless. For those even remotely interested in digital interactive advertising, iAd really is a game changer. Whether it will be successful or not is a question, but definitely a revolutionary approach to mobile advertising.
Even though many claimed to have done innovative creatives around interactive advertising, I really haven't seen anything close to what Apple demoed in this event. You basically stop what you're doing to interact with.. basically a promotional content.
For free app developers, the only way to monetize on their sweat and effort is by selling advertisements. (actually there are others like sponsorship. Let's get down to those minor categories later) The irony is that all those cool, free apps are stuck with banner ad impressions (okay, what about CPC? Points taken, but it's still static). From the consumer point of view, we can either simply ignore or click the banner to make a purchase. This is a crappy buying experience. The big missing piece here is that banner ads suck at marketing products. They just ask you to get your credit card number out.
This is where iAd comes in. Okay, I'm sold on this cool banner. So, I click into it. Rather than showing me the "Buy Now" button, show me something else. A well-made iAd can be a full-fledged platform to experience the product and brand. The Toy Story example had gaming component, free wallpaper.. things that I can interact with. Yes, there's a "buy now" component, but it's not the only thing in there.
Some iAd opponents argued that this is a stupid idea because people just don't want to stop what they are doing to get into an ad. This is true, because mobile ads really suck now. Think about Super Bowl ads. People expect good stuff, and the value of those ads go up proportionately. If advertisers, as a whole, can serve high-quality experience through iAd, maybe this is something that consumers don't mind giving up leaving the app for an ad.
Of course, whether there'll be good iAds or not is a big hole here. Apple created the platform. Now it's up to advertisers and marketers to make iAd successful.