Apple's announcement of the 'Optimized for iOS7' mandate is as follows:
https://developer.apple.com/news/index.php?id=12172013a
Starting February 1, new apps and app updates submitted to the App Store must be built with the latest version of Xcode 5 and must be optimized for iOS 7. Learn more about preparing your apps by reviewing the iOS Human Interface Guidelines.
There's been several questions regarding this already regarding the Xcode part, which seems fairly straight-forward (use Xcode 5!)
But the 'optimized for' part along with the HIGs is much more vague.
It appears that some interpret this to mean "It has to look like a native iOS7 app...Helvetica Thin, extremely flat icons, translucency, etc"
But I find that hard to accept given how broad app UIs tend to be. I don't see EA Sports changing all their UIs to match, for example. Has apple published any clarifying documentation in regards to what they mean by 'optimized for' and how closely the UI must adhere to iOS7 conventions and to what range of apps this would apply to (all apps? Only native apps? HTML5 apps? Games? etc.)?