Not. Piledriver is a micro-architecture code name similar to "Sandy Bridge" , "Ivy Bridge" , "Haswell" on the intel side. Just like Intel the basic micro-architecture, with some minor adjustments, is used across the whole CPU product lines. For example,
http://www.anandtech.com/show/6430/amd-launches-opteron-6300-series-with-piledriver-cores
Similar to Intel the architecture rolls out slower to the Server variants. That is mainly a issue of demand, process technology yields , and size of the respective products. ( growing mobile, smaller dies have better yields, fewer cores leads to smaller dies ).
And yet Linux , Windows , etc. all manage this with little to no difficulties. Talking a very small subset of privileged mode instructions. Normal apps (which is a large bulk of what folks sweep up into the umbrella of SO ) don't really have any differences ( can play with optimizer settings. and Intel's compilers won't do a good job but this is not a "loose sleep" issue).
Apple is far more likely not to switch to AMD because they can't switch all of the x86 CPU purchase orders over to AMD. Apple's buying cloak with Intel helps them influence things like a more aggressive stance on integrated graphics, but far more it gets them discounts. Apple is Scrooge McDuck when it comes to saving money.
----------
AMD cores don't have as high of throughput. They generally have more in the Opteron space but not necessarily better ones. They also tossed SMT/hyperthreading so matched in contexts were this is significant memory latency generated by branching/varying memory access driven by workload.
Many computational benchmarks have Intel generally out in front in terms of $/performance .
If just counting cores , without respect to performance , then the GPGPUs have both of them beat. If an embarassingly parallel float workload then both on performance, core count, and $/perf .
