We already knew that Don't Starve was heading to the Wii U on May 28 (June 4 in Europe), but now we can confirm that developer Klei Entertainment has sweetened the deal a bit.
If you buy the game for $14.99 before June 28th, you'll get another copy for free in the form of a code. Basically, think of it like a Steam double-pack, so you can split the cost with a friend or just gift it.
I hope that this promotion paves the way for Don't Starve Together on consoles at some point. Right now the multiplayer expansion is only announced for the PC.