Oh boy. We've had plenty of Xbox 720 rumours to pick apart over the last few months, but this latest report is an absolute doozy. According to tech site SemiAccurate, Microsoft may be forced to delay their next-generation console due to "painfully low" processor yields in the manufacturing process.
That said, since the rumoured delay is technically for an unannounced console without a release date, I daresay that few people will lose sleep over this one yet.
SemiAccurate reports that "multiple fabs" are producing an Xbox 720/Durango chip codenamed 'Oban,' which is simply not living up to expectations. Yields (usually a measure of processing power, but in this case, the ratio of viable chips produced per production batch - thanks ImNotHere) have been described as "painfully low" and "horrid." Microsoft has allegedly outsourced production to three separate factories to find a solution ahead of a planned September 2013 launch window.
Apparently Microsoft's manufacturing chain has a built-in six-to-eight week buffer zone that gives them time to sort out any problems before resorting to a delay. Should they not correct the issue before November 1st, however, they may have to delay the launch - potentially into 2014.
This ought to go without saying, but just in case: this is a rumour. You can read more over at SemiAccurate.