I'm not decided by any stretch, but I'm certainly leaning to Obama despite his weak resume. This long essay by Andrew Sullivan captures my mood pretty well.
But if you sense, as I do, that greater danger lies ahead, and that our divisions and recent history have combined to make the American polity and constitutional order increasingly vulnerable, then the calculus of risk changes. Sometimes, when the world is changing rapidly, the greater risk is caution. Close-up in this election campaign, Obama is unlikely. From a distance, he is necessary. At a time when America’s estrangement from the world risks tipping into dangerous imbalance, when a country at war with lethal enemies is also increasingly at war with itself, when humankind’s spiritual yearnings veer between an excess of certainty and an inability to believe anything at all, and when sectarian and racial divides seem as intractable as ever, a man who is a bridge between these worlds may be indispensable.