I have just installed Xcode 4.5 for iOS6 support, and I have seen a new icon called \'Exit\' in my Storyboard, listed under my view controllers along with \'First Responder\
See also Cannot Connect Storyboard Unwind Segue which clarifies the requirements to bring the Exit icon to life. You must have, higher up in the view controller hierarchy, a method that is:
Marked as IBAction
Takes one parameter that is a UIStoryboardSegue*
If both those conditions are met, the Exit icon will see it and will permit you connect through to it by control-dragging from a button in the same view controller.
I have also now posted the world's simplest example here:
https://github.com/mattneub/Programming-iOS-Book-Examples/tree/master/ch19p638presentedViewControllerStoryboard (fixed 12 July 2013)
This shows how trivially easy it now is to segue to and back from a presented view controller, as opposed to all the work you had to do previously in order to hand info back and forth (the stuff in the template with a delegate and a protocol, all of which can now be deleted).