Xbox One will not support external storage capabilities at launch while the PS4 does not permit external harddrive game installation; it has emerged.
Both the Xbox One and the PS4 will ship with 500GB harddrives and while you can swap the PS4's HDD for a larger one the Xbox One's harddrive cannot be removed.
Speaking during a PAX Prime podcast this past weekend Larry 'Major Nelson' Hryb said at the 37 minute mark that:
"The future plan is for definitely to support external storage much like we do on the Xbox 360.
"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."
Sony's Shuhei Yoshida has meanwhile confirmed that you will not be able to install PS4 games to external harddrives.
@_Tracid_ no
— Shuhei Yoshida (@yosp) August 31, 2013
Given that games must be installed on both next-gen systems it seems 500GB may not be enough for some more profilic gamers but presumably both Sony and Microsoft are looking at a number of options, including cloud storage.
Both the PS4 and Xbox One are set to be released this November for $399 and $499 respectively.