But for this preorder period, Telltale is having a contest. Everyone who preorders the game or (for the mandatory 'no purchase necessary' requirement) sends a postcard to Telltale before the 4/23/12, will be entered into a chance to become one of the undead in the game. The winner will appear in episode 4 first as a human, then as a member of the undead. Up to four others will become a member of the undead horde, seen shambling around in the game (or perhaps eating an unfortunate victim).
For your chance to become part of the walking dead, preorder here.