has announced that a new patch for Dungeon Defenders
is now available via Steam, adding the new Jester Hero DLC, along with Fool Costume, and "The King's Game" mission & associated loot. Also, the 'Dungeon Defenders Development Kit' has been moved to the Steam Tools section, rather than being a Dungeon Defenders DLC. Any previous owner of that DLC should re-download it as a Tool.
A playable demo can be found here