Microsoft has yet to give an official announcement about its plans for a successor to its Xbox 360 console. However, the rumors of that console (called Xbox Next or Xbox 720 in the media) have continued to hit the Internet. The latest such rumor comes from SemiAccurate.com which claims via unnamed sources that production has now begun on the processor, coded name Oban, at an unnamed foundry.
The story further claims that 10,000 wafers of the processor are being made, with the conclusion that these chips are being created for installation in official Xbox Next/720 game developers kits. It claims that the production of these chips actually started at the end of 2011 and that the first chips will be ready to go sometime in late February. The article speculates that development kits with these chips could be ready to be sent to game developer studios in March 2012.
The article also speculates, and many other people agree, that Microsoft will once again have a PowerPC-based CPU for the next Xbox processor, just as the Xbox 360 has one based on PowerPC's design. Xbox Next/720 might also have a Radeon-based graphics chip from AMD.
Again, this is all rumor and Microsoft is likely not to confirm anything about the next version of the Xbox until E3 2012 in June at the earliest.