Apple Testing ARM Based Mac Prototypes

I'd be surprised if they didn't have prototypes running on ARM processors. I can already imagine their marketing for a Macbook Air that runs for a week on a single charge.

Of course such a transition would require developers to re-compile their software for the new platform, though I imagine Apple would make "Rosetta 2" to run x86 software of ARM processors.

I wonder how much Apple cares about users not being able to boot Windows. I suspect not much.