Of course Apple is exploring the possibilities of utilizing their own ARM based CPUs; that’s a no brainer when you have your own CPU team. Why wouldn’t you consider it? But I also know Apple won’t go down that path if Intel keeps ahead of Apple’s own efforts.
The bullet point benefits (energy & cooling efficiency) of moving to an ARM processor for their Macbook Air is tempting but if they’re sacrificing performance for these gains. However, it’s going to be really tough for them to stand up on stage and sell the loss of x86 compatibility and performance.
Maybe it isn’t a viable option now but maybe it will be viable in a few years. Who knows? This could also be their passive aggressive way of lighting a fire under Intel’s bottoms and convincing them to be more aggressive with their pursuit to low power, high performing chips.