Yes, the power utilization is apparently much lower for A12 vs A11, and as mentioned, A11 is probably not cheaper to produce than A12. Furthermore, there is a huge improvement in GPU performance in A12. Thus, there is basically no reason to go with A11 for any future products.
That said, even A10 performance is still fine for most entry level users. BTW, I just picked up a 2 x dual-core Xeon 2.66 GHz Mac Pro, and A10 is actually faster than that machine in Geekbench 5.
The iPad is about twice as fast as the Mac Pro for single-core, and about 10% faster for multi-core.
775/1400 - iPad with 2.33 GHz A10
370/1270 - Mac Pro with 2 x dual-core 2.66 GHz Xeon 5150
If I were to buy replacement quad-core CPUs for this Mac Pro to bring it to 8 cores, it'd only be about as fast as A12 multi-core.
That said, even A10 performance is still fine for most entry level users. BTW, I just picked up a 2 x dual-core Xeon 2.66 GHz Mac Pro, and A10 is actually faster than that machine in Geekbench 5.
775/1400 - iPad with 2.33 GHz A10
370/1270 - Mac Pro with 2 x dual-core 2.66 GHz Xeon 5150
If I were to buy replacement quad-core CPUs for this Mac Pro to bring it to 8 cores, it'd only be about as fast as A12 multi-core.