This polls junk and even Andy Smith who works in the poli-sci department at UNH (though I didn't have him as a professor) will probably tell you that, like he did the last poll that was O+5. Romney, Obama and Biden were both here on September 7th. Biden and Ryan have been here every 2 weeks since. Chris Christie has been to the state. Bill Clinton is coming on Wednesday (and they wouldn't deploy him here unless they needed him. I think the internals are pretty bad for dems judging by the number of appearances they're making, and anecdotally, it isn't looking too pretty (though I know that isn't a good measure).
Collapses happen, and Obama up 15 in New Hampshire is consistent with the Quinnipiac polls for Florida, Ohio, and Pennsylvania today. Neither U-New Hampshire nor Quinnipiac has been particularly D-friendly to date in polling results.