Minecart with Dispenser

Minecarts with Dispensers are unimplemented vehicles that, as the name implies, is a dispenser in a minecart.

Other than the screenshot shown below, no detail about its use, function, or activation method were published.

Trivia

 * In 1.5, ability was added so with third party programs, you can put any block in a minecart, and dinnerbone was most likely demonstrating that functionality with the dispenser cart