IGN is reporting that the next Xbox will ship in autumn 2013, with a GPU based on AMD's 40nm Radeon 6000 architecture and allegedly offering performance akin to the Radeon HD 6670 from last year. "Sources close to the project" are offering a ballpark figure of a six times performance increase over the Xbox 360, or 20 percent more power than the Wii U, though this doesn't really tell us anything in real terms. All this should obviously be taken as rumor and speculation, but it's worth noting that IGN broke reasonably accurate information on the Wii U months before its official unveiling last year.
No details were given on a possible CPU the console would ship with, but if true, the report would mean that the next Xbox's theoretical power is unlikely to outstrip the gaming PCs of today. Of course, in practice the fixed and dedicated nature of console hardware means that developers are able to wring far more performance out of them than they would get from an identically kitted-out PC. Moreover, the majority of PC games today are limited by the need to run on consoles as well, meaning that they're effectively hamstrung by hardware more than five years old, and their performance advantage is often largely limited to resolution and framerate. A new Xbox running this hardware should be more than capable of catching up to and even exceeding almost all current PC games, but would also push the baseline forward for future PC development.