Biden will be his typical self. But he will be MUCH more aggressive. This is exactly why he will do more harm to Obama than Obama even did to himself.
Biden has somehow garnered an image as an affable guy; a real mensch. But that whole avuncular style of his is just an act. He is a BS artist of the highest order. He is also arrogant and condescending. Go back and watch some old video footage of his performance in the Bork and Clarence Thomas hearings. He is a grandstanding, pompous blowhard. Always has been.
He's going to step on his **** more than once in this coming debate. His performance will leave Americans thinking "This guy is a joke! Do I REALLY want to have him a breath away from being president?"