Tons of rumors have been flying around here for more than a year and given Apple's secretive nature I suspect this story will be more speculation than anything for some time to come.
That said, it makes sense Apple would want to ween itself from dependance on its archrival Samsung to make its chips, the secret ingredient of its products. TSMC and Intel are the logical choices.
If I were Samsung I'd do an Apple and just chop them. The Cupertino boys would get a taste of their own medicine. When you see how many suppliers they stiffed over the years it would be such a hoot to watch
I'm not too sure about relationship with Intel. After all, Intel makes processor and very eager to get a chuck of mobile device market. In Apple point of view, Intel is not an ideal partner. With this in mind, I'm sure the "independent" foundry would have an advantage to strike a partnership deal with any MCU design house.