Are you worried about piracy or that your app may not be available to all platform users anymore? I bet that immediately after this feature comes countries, mobile providers, etc. will roll out their own app stores and many users will not go with Apple's. Those stores will probably incentivize big apps like Facebook get on them but not regular solo developers. You may have to distribute your app through a dozen of app stores and comply with all their differing regulations and review processes instead of one, or pass on user share... (Or more likely you'll need to pay up some app store distribution middleman who will capitalize on the situation)