> Why should Apple be responsible for making sure their Safari promotion showcase works perfectly in every other browser?

Because the whole point of the exercise is to show how standards-compliant, open, web apps work so great on iPhone OS. Except by excluding every browser but Safari, it may as well be a front for the App Store. It might be standards-compliant, but it sure as heck isn't open or inclusive. In that regard, even Flash runs in more browsers than this showcase does.