Definitely a mistake on MS' part to not officially support HDD replacement on the Xbox One. 500GB is nothing when your installing 25GB - 50GB games, music, and movies. I have a 2TB on my desktop PC build, and still can't install my entire Steam library. For guys like me 500GB just isn't gonna cut it. I'm sure we will know soon though if the HDD in the One is truly upgradeable or not.