Like it or not, all iOS 6 apps will need to be upgraded for iOS 7
Apple isn't making it a requirement, but it's something every developer should do anyway: because when you put an iOS 6-designed app next to an iOS 7-ready one, the difference will be incredibly stark -- and not in a good way.
http://feedproxy.google.com/~r/TheAppleBlog/~3/Qp38B6XcUzY/