Do the Apple App Store guidelines approve of submitting an app that uses Swift right now?
Swift can run on all devices running iOS 7.0+, so if I submit an app that uses Swift before iOS 8 is released will it be rejected?
Do the Apple App Store guidelines approve of submitting an app that uses Swift right now?
Swift can run on all devices running iOS 7.0+, so if I submit an app that uses Swift before iOS 8 is released will it be rejected?
Apps written in the Xcode 6 Beta will not be approved so you have to wait for the new Xcode to be released before submitting apps with Swift code
To submit with Swift you'll have to build your app with the iOS 8 SDK, even if you want to target devices running iOS 7. Apple are not accepting submissions built with the iOS 8 SDK, and probably won't for some time (until the SDK goes GM).
Considering that you'd have to use XCode 6 (which is beta), iOS8 base SDK (which is beta), and that the language itself is likely to undergo significant revisions & changes between now and public release, I'd say it'd almost certainly be rejected.