Online (and brand) marketers should be pretty excited about Apple's entrance into the ad business. Why?
One of the biggest obstacles online faces is the lack of a simple, powerful creative standard for online advertisements. We need a standard that is as simple as the 30-second TV spot...but at the same time is as emotionally compelling and far more engaging. We also need to engage creatives in a way that to-date we haven't really been able to do.
Apple has a history of solving exactly these types of problems. They almost always win with a formula (for products, services, etc.) which is simple, creative, standardized and consumer-centric. If they do this for the iAd (on iPhones, iPads and iPod Touch), I am certain they will soon extend it to the web...and we will all be winners.