The emulation question is the main reason -- not the only reason, but the main reason -- I don't see Apple really moving in this direction with the Mac line any

The emulation question is the main reason -- not the only reason, but the main reason -- I don't see Apple really moving in this direction with the Mac line any time soon. But I don't think it's just a matter of third-party software for OS X that's the issue; Windows compatibility is a pretty big deal. Apple doesn't push Macs as being great Windows machines currently (although they did for a while), but they're certainly aware of this use case and how it's been a minor but measurable plus for the Mac line. Even as much as Apple is known for burning down the old to make way for the new, I think they'd be pretty cautious with this one. The notion that this CPU is really about giving ample power to the iOS line makes more sense to me. There will eventually be an "iPad Pro," whether or not it gets stuck with that moniker, and it won't have to worry about backward compatibility with anything other than previous iOS devices.