ivanpgcs on 20 January 2011
The bonus pack is for preorders in all version of the game. i think that the normal edition of the game also includes the bonus pack.
http://www.gamestop.com/Catalog/ProductDetails.aspx?product_id=77979#bonusFeatures
http://www.walmart.com/ip/Killzone-3-Walmart-PS3-PlayStation-3/15413653
http://blog.us.playstation.com/2011/01/14/killzone-3-gone-gold-kicks-your-face-in-february-22nd/
so if you preorder the game = 10 maps
