Note that Apple now keeps the previous version of the app around for users on older OSes. Of course they won't get any of the upgraded features, but at least there's still something there for them - and you won't have to worry about all that messy code for supporting multiple versions.
My next app updates will also be iOS7 only, since I know the iOS6 version will still be around. Makes it much easier to decide to use newer features.
My next app updates will also be iOS7 only, since I know the iOS6 version will still be around. Makes it much easier to decide to use newer features.