For all his gaffes, for all his goofiness, for all his Joe Biden-ness, I can't for the life of me imagine why any pundit or consultant worth his or her salt would propagate the rumor that Hillary Clinton should or would replace a guy who can give a speech like this.
Biden may have his faults, but I think he tends to be underrated by those of us in the chattering class. Certainly President Obama talks about seeking his counsel, praising him in Charlotte as a better vice president than he could have hoped for. And certainly Biden has enough legislative experience, connections, and common touch, to be a top White House asset rather than a liability.
And he's got something on display in this speech, something for which there's no substitute: heart.