iOS devs can finally claim functionality that our Java counterparts have been taking for granted: "nullable" annotations in ObjC which transfer to Optional Swift types https://developer.apple.com/swift/blog/?id=25!
I hope we can start using these in our app ASAP. It will help ObjC dev efforts a ton while also easing our (not too distant) transition to Swift. I *think* that all we need to do is specify Xcode 6.3 as the *minimum* *supported* Xcode version. I'm guessing lesser versions will fail to compile the code if they encounter one of these new pragmas or annotations.