Minecart with Dispenser

Minecarts with Dispensers are unimplemented vehicles that, as the name implies, are minecarts with Dispensers in them.

Other than the screenshot tweeted by Dinnerbone, no detail about its use, function, or activation method were published.

Trivia

 * In 1.5, it was made possible to, by editing NBT tags, put any block in a minecart. Dinnerbone was possibly demonstrating that functionality with the dispenser cart.