Darksiders 2 is coming to the Wii U a bit later than the other consoles, but THQ and Vigil Games are packing in a few extra goodies for the wait, in the form of pre-order bonuses bundled all together.
On the PlayStation 3 and Xbox 360, you had to pre-order to get an access code for the Argul's Tomb DLC, but it will be included with the Wii U whether you pre-order or not. You'll also get some retailer-exclusive pre-order bonuses: the Death Rides Pack, the Angel of Death and Shadow of Death packs, and the Deadly Despair Pack. These grant you three additional side-quests, sets of early legendary armor and weapons, and a speed boost to your horse, respectively. The announcement also promises additional unique legendary weapons and armor sets, but doesn't specify what they are.
The announcement also mentions using the Wii U GamePad to access inventory and abilities, which may cut down a bit on the menu sorting of the other versions.