Anand Lal Shimpi, after seeing the new single-core A5 and measuring that its Apple TV draws much less total power:
The implications of this smaller, lower power A5 SoC are unclear to me at this point. It seems to me that the Apple TV now sells well enough to warrant the creation of its own SoC, rather than using a handmedown from the iPad/iPhone lineup. The only question that remains is whether or not we’ll see this unique A5 revision appear in any other devices. There’s not a whole lot of room for a single-core Cortex A9 in Apple’s existing product lineup, so I’m encouraged to believe that this part is exclusively for the Apple TV.
I’m still torn on this. I bet that if Apple engineers a whole new device to be the “cheaper iPhone” rather than continuing to sell old models, or if they do a similar move for a future cheaper iPad Mini, this would be an obvious CPU candidate: not only is it tiny, cheap, and fast enough for an iPhone or iPad while leaving a big enough performance gap to drive higher-end buyers to the higher-priced products, but the low power requirements would let Apple shrink the battery a bit, further reducing weight and cost. Every cent matters at Apple’s scale.
But the fundamental assumption I made when this CPU was first rumored — that the Apple TV sold too few units to justify its own custom CPU — was probably wrong, leaving a very boring, plausible explanation for this new CPU that has nothing to do with future iPhones or iPads.