well, we know that zombies will be in the game, and that we can potentially raise units from the dead:
Can we raise the dead? “Yes …it has to make it in, we don’t know how, but it has to make it in. There will be some way, you might not
like it. Maybe this is how the zombie apocalypse starts … maybe the
penalty for losing someone is that you have to ‘res’ them, and
‘ressing’ them too often could turn them into a zombie … zombie
apocalypse should be a way to lose the game”
so the idea of a graveyard isnt entirely out of the realm of possibility… 