We don't have to parse polls too much longer - all we need to do is watch where the candidates are heading and the reception they are receiveing at these events. By the end of September or the beginning of October we will know who is ahead between Obama and Romney as neither candidate will be spending time and money in a state they think they are likely to lose.
If Romney is in North Carolina during the first week of October (which I don't think he will be), Romney is clearly losing. If Romney is in Virgina, Ohio or Florida that first week of October then he is behind as, for all practical purposes, those are three states Romney must carry. If, on the other hand, Romney is in smaller swing states such as New Hampshire, Iowa, Colorado, and Nevada the first week of Oct then Romney has a small lead. And, if Romney is in Wisconsin or Michigan then he is clearly winning.
Obama, on the other hand, may be in states he is losing - such as Virginia or Ohio simply because he must win those states. I personally don't know how he will react to being down. He doesn't seem to have the strength to handle such adversity gracefully. I think his rhetoric, and that of the press, will get ever more shrill, ever more outlandish. We may see the far left-wing of the Democratic Party suffer a nervous breakdown. four years earlier Democrats dreamed of their ultimate victory and now, everything falls apart.