IMHO: Apple will split CPU manufacturing between TSMC (low end) and INTC (high end)
ARM based CPUs will be in lower end devices; iPad, iPhone, and new MacBook Ether, essentially the answer to the Chromebook.
INTC will maintain the high end MacBook Air and Pros.
Apple reduces dependence on Samsung and spreads risk between TSMC and INTC. INTC, as we know, will have no problem with capacity. Even if TSMC has issues, and we know they do, with 20nm, it really won't matter for the iPad or MacBook Ether as they are low power devices.
If Apple decides to put the full OS onto an iPad, I'm sure it will be an INTC chip. If Apple decides to make cheap iPhones, I'm sure it will stay an ARM chip.
Having the high end covered and low end on contract gives Apple the ability to expand in either direction. It's a smart move by Apple.
When the rubber hits the road and INTC's Bay Trail, et al, gets some traction, it will be an easy switch to INTC--and by easy I mean there are engineers already working on the solution.