* Android App Store/Google Play becomes a viable business proposition
* Windows App Store becomes a viable business proposition
* Blackberry App Store becomes a viable business proposition
* The demographics of Apple device owners shift away from the current favorable, affluent, app-buying profile
* The app screening process gets easier, such that malware and other liability-causing software infests it the way that Google Play is infested (and remember, Apple and Disney are longtime buddies and Apple is working a lot harder for media companies' cooperation than Google is)
* The developer program entry barriers become something that bother serious coders already invested in the Apple ecosystem, as opposed to random grumpy developers on the Internet (it is rarely a good business move to treasure the opinion of people who aren't your customers and don't intend to become customers)
Currently, none of these things have happened.