New Binding of Isaac DLC

The new Binding of Isaac: The Wrath of the Lamb is coming out on end of may. Probably you're thinking what they are bringing into the game after the big amount of items and  dungeons on the game.
But yes they are bringing with this DLC 50% more content to the game.
McMillen said to the new DLC that is supposed to be a thank you message to the fans.