http://www.ztgd.com/news/11431/dead-island-coming-to-playstation-home/
Certain items in the PlayStation 3 version of the Dead Island will only be obtained through this PlayStation Home event. Each week will introduce more levels and unlockable content including a premium PlayStation Home reward "Exploding Zombie Outfit" for players that pre-order Dead Island directly from Home's Central Plaza and the aforementioned "Exploding Meat", a powerful weapon for use in Dead Island that can only be acquired by surviving the PlayStation Home onslaught.