I've had half a dozen or so early morning delays out of a hub get popped back to their regular time. I woke up to one a month ago or so, only to see it get popped back once I had actually woken up; they took the crew from another flight and delayed it instead.
Geez... if that were to happen there would then be a 4 or 5 hour layover in PHX as they rebooked us onto a later flight since the connection was going to be missed.