According to Gearbox Software's Twitter account, a Game of the Year Edition of Borderlands will be out in October.  It'll include all four DLCs and a bonus map for Xbox 360, PS3, and PC.

The GotY Edition comes with The Zombie Island of Dr. Ned, Mad Moxxi's Underdome Riot, The Secret Armory of General Knoxx, and Claptrap's New Robot Revolution.  The Claptrap DLC isn't out yet, but will be out in September if you can't wait for it in the GotY Edition.

There's no word on what the map is or on the price point yet.  Hopefully, it will be all that the vault hunters could wish for meaning it should rain loot and money.

If you need some background on the game or each of its DLCs check out the official site.