I've looked around and haven't seen this posted, so I thought Id share it. Per Ben Smith, it was made by a prescient college kid back in January. I think the campaign should get permission to air it.
http://www.youtube.com/...
I don't know about you, but that gave me chills when I watched it. It captures exactly the right tone. Energetic, forceful, and optimistic. I particularly like the alternation of Biden and Obama. I also like that it shows that this is not a one issue campaign.
The only thing I'd change is I'd swap out the "Darfur" text for "Genocide" or something similar. The picture is fine, but I think the focus should be broadened beyond just Darfur. Other than that, I just can't think how you would make a better overall ad for Obama/Bden.