The Xbox One won't support future modular upgrades, as reported by some publications following comments made by Xbox boss Phil Spencer at a recent Microsoft event.
"Am I going to break open my console and start upgrading individual pieces of my console? That's not our plan," Spencer explained on the Major Nelson podcast. "There is something special about what happens with a console. You buy an appliance-like device; you plug it into your TV; it works when you plug it in. It's not like I'm going to ship a screwdriver set with every console that comes out."
That's not to say Spencer's original comments relating to hardware updates doesn't stand.
"What I'm saying is as hardware innovations happen we want to be able to embrace those in the console space," Spencer added. "And make those available and maybe not have to wait seven or eight years for things to happen. But right now, we're not announcing hardware."
An Apple-like approach to the Xbox, with regular iterations of the system would appear most likely. Spencer previously spoke about games being both backward and forward compatible, much like App Store purchases.
Source: Major Nelson via GameSpot