Intel never managed to get their bread-and-butter chipset business into the iPhone, which has always been all-in on ARM. A new rumor, however, suggests they may have a second bite at that Apple - with the radio. Anton Nehaenko for Kommersant (translated):
According to information received from several sources in the software development industry and the production of smartphones, Apple is in the process of selecting a vendor whose products are replaced in smartphones and tablets iPhone iPad chips made by American Qualcomm. The fact of finding a replacement source also confirmed in a U.S. cellular operators. [...]
One of the injured party here is by Intel. Coming out of the production of chips for mobile devices in 2006 with the sale of units XScale, Intel has returned to this theme through the purchase in 2010 of German Infineon - chipmaker cellular system installed in the first few generations of iPhone.
There's been a lot of chipset drama over the years, most recently with the will-they-won't-they leave Samsung for an alternate fabricator. Apple famously switched to Intel from PowerPC for CPUs on the desktop, and from Infineon to Qualcomm on the iPhone for radios. They'll go where the best, most efficient technology takes them.