The Xbox One won't support external storage solutions when the console launches later this year, Microsoft spokesperson Larry "Major Nelson" Hryb confirmed during a live recording of his podcast at PAX Prime 2013.
Responding to a question from an audience member, Hryb explained that the company plans to allow Xbox One users to utilize external hard drives if they need more space than the console's internal 500 GB hard drive allows. However, he didn't think that feature would be available at launch.
"The Xbox One will ship with the 500 GB hard drive, all of them have that," Hryb said. "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."
In May, senior director of product planning for Microsoft, Albert Penello, confirmed that the USB 3.0 ports in the back of the console could be used for external hard drives, but that the console's native hard drive would not be removable. We've reached out to Microsoft to find out when external hard drives will be supported for the console.