According to the latest information, it appears that both sides had wanted to pull the trigger on this deal much earlier, but at the time TSMC could not produce chips with the power and speed required by Apple. The deal that both parties agreed to will not take effect until next year which means that at least for one more cycle, Apple's new mobile devices will be powered by arch enemy rival Samsung. Apple still sources some of its components from the Korean manufacturer, but has turned to firms such as Toshiba for flash memory, and LG Display, Japan Display and Sharp for panels.
TSMC started talking with Apple as early as 2010 about supplying the company with chips, but company CEO Morris Chang turned down Apple's request to have manufacturing space set aside for it and also rejected Apple's offer to make an investment in the project.
While Wednesday's story said that TSMC would start rolling out its 20nm Ax chips by this September, Friday's report says that the silicon won't be available to Apple until next year leaving Apple no choice but to stick with Samsung for the remainder of 2013.
source: WSJ via AppleInsider