I predict the opposite - O'Neill had lost all of his bounce and enthusiasm, two of his trademark attributes. Who knows what he was having to deal with behind the scenes as well as a very average team who are not as good individually as they probably think. Di Canio won't put up with prima donnas for more than a minute and will take a lesser player with the right attitude over one with delusions of grandeur.
One thing is for certain - colourful times ahead for Sunderland, I wish them well
Also Martin, I hope he gets his hunger and enthusiasm back, and another club should rekindle his fire.