Sorry, but he's a dude. and i vote never. i don't want to see his face. everyone knows him for his helmet. not showing his face also serves the goal to connect the player to the Chief. Our imaginations fill in his face. if they show his face, people might get disappointed. i even vote not for the final game, weather or not he dies. i think Reach had it right with the ending cutscene. they never showed his/her face. i think this would fit the Chief.