Just saw this on Way Too Early. Have not seen it as an actual ad yet.
A partial transcript below the jump for those who need it.
The ad begins by describing convicted "gluttons of greed" such as Bernie Madoff and Kenneth Lay and cheekily says only "One man has the guts" to speak the name of "evil genius who towered over" them: Big Bird. The ad continues with clips of Romney saying "Big Bird", followed by a clip of Big Bird saying, "It's me, Big Bird."
"Big, yellow, a menace to our economy," the ad jokingly continues. "Mitt Romney knows it's not Wall Street you have to worry about, it's Sesame Street."
"Mitt Romney, taking on our enemies no matter where they nest."
The Obama campaign tells CBS News that the ad will run on national cable and broadcast but would not indicate how much the ad buy is or where exactly it will be airing.