This is over.
It has been over since the February landslides. If you remember the the "leaked" memo from the Obama campaign with their post-Super Tuesday projections, http://www.politico.com/... Obama has not lost anywhere he did not expect to lose. He has gotten more delegates than he had projected in virtually every state.
So what are the Supers waiting for? Up until now, many of them are waiting out of courtesy to the Clintons, who have a long history in the party, and have appointed many of them to one position or another over the years, or given a favor or two. But they know that she will not win.
Unfortunately, given the political calendar, there has not been an occasion for another "big" Obama win for about 2 months now. But now North Carolina is the biggest state left on the calendar, and Obama will win it, as he has always been expected to. And then it will be clear that Obama will win the pledged delegates, and every real measure of the popular vote, whatever happens in the few smaller remaining states.
And then the Supers will either flock en masse to Obama, or will signal to the Clintons that they intend to do so shortly. Either way, Clinton drops out shortly after North Carolina. This will take about 48 hours after the North Carolina primary or about two weeks from today.
Now, if Obama also wins the Indiana primary the same day, I would revise this prediction, and say that Clinton concedes within 24 hours, which means her campaign only has 13 days left.