I'd really like that 1970's suit(The classic blue!) These skins are rumored to be timed exclusive skins.
United States
Amazon: $10 promotional credit, and exclusive Batman: Arkham City comic (with Xbox 360 and Playstation 3 versions only).
Gamestop: exclusive Joker’s Carnival challenge map (reported 4 hours of gameplay).
BestBuy: exclusive Robin character with his own unique gadgets and moves. Playable in all challenge maps of the game, including two additional maps that are only available with BestBuy preorders (Black Mask Hideout and Freight Train Escape).
Newegg: free Batman t-shirt with console versions of the game.
Walmart: $10 eGift card and a free copy of Batman: Arkham Asylum with console versions of the game.
United Kingdom
ShopTo.net: exclusive 1970′s Batman Suit DLC. This store also offers a Two-Face SteelBook edition for a slightly higher price.
Blockbuster: SteelBook CE of the game featuring the Penguin (Xbox 360 only).
Tesco: Joker’s Carnival challenge map, and SteelBook case with Joker cover art.
GAME: playable Robin character with two challenge maps and two costumes. This edition of the game also features Robin box art.
GameStop: exclusive “Batman Beyond” Batsuit DLC.