I cannot see any change happening with a Republican president. And even if Obama wins I am not sure that online gambling will be regulated in America any time soon. Important players in the political landscape need to support online gambling for positive change to happen and I cannot see any signs of that. Some congressmen like Barney Frank speak in favour of legalization and regulation, but they are a minority and none of them have a high place in the political landscape.
The only realistic scenario where change can happen is not from within but from the WTO where a large number of countries currently challenge the United States over its protectionistic approach to online gambling. But honestly I do not believe that a large world-wide trade dispute will start over online gambling. A sollution where the US will pay some form of compensation and in return be left alone seems much more likely.