Look for a 1-2 punch. First this story released through a right wing outlet, then a scond story (or a strong rumor of one) just as he starts to get his legs back under him.
This is tricky because Hillary has to make it look like a Republican dirty trick while she is the one who benefits. If Obama doesn't get the nomination there will be rage in the black community, so she has to get it directed at Republicans. Her trump card is that the DNC and MSM will have to cover her tracks for her. If they expose her they risk losing the black vote for a long time.
Very good point. There is no more shame in politics anymore. If this tape was released now Obama would try and ride it out till the convention. If it is released right before the convention the superdelegates might see no other option other than abandoning Obama.