I don't remember if this was announced this week; does Swift 2.0 work back to iOS 7?
Swift 2.0 in iOS 7?
Perhaps more importantly, will the iOS 7.1 simulator still be supported from Xcode 7. I can't currently get it to work, despite being recognized by Xcode.
I haven't tried it, but this other thread, https://forums.developer.apple.com/message/6407#6407 implies that as of beta 2 its working on iOS 7. So that implies that in answer to your question, Swift 2.0 does work with iOS 7.
Can someone confirm?