The Xbox One will not support external storage at launch, Microsoft has confirmed.
All Xbox One units come with a 500GB internal harddrive, but this cannot be replaced. In May, when the Xbox One was unveiled to the world, Microsoft said you'll be able to use the console's USB 3.0 port for external storage, and use that for game installs and downloads.
This won't be a feature supported at launch, though. "The future plan is for definitely to support external storage much like we do on the Xbox 360," Microsoft's Larry "Major Nelson" Hryb said during a podcast conducted at PAX over the weekend (skip to the 37 minute mark).
"My understanding is that feature will not be there at launch because the team is working on some other things, but it definitely is on the list. I don't know when it will come in though."
Meanwhile, Sony has confirmed that you cannot use an external harddrive to install PlayStation 4 games.
"No," was Sony Worldwide Studios boss Shuhei Yoshida's succinct response to a follower question on Twitter.
As with the Xbox One, the PlayStation 4 comes with a 500GB harddrive. Unlike Xbox One, the PS4's internal harddrive is replaceable.