I'm not sure it'll have a big effect on software. The vast majority of application software will work the same, only with fat binaries containing both x86 and A

I'm not sure it'll have a big effect on software. The vast majority of application software will work the same, only with fat binaries containing both x86 and ARM code. The few bits that are optimized for particular CPUs, like video codecs, already exist for both CPUs. The most likely opportunity is applications that are currently too sluggish except on big Mac Pros, but would be more popular if people could run them on cheap ARM macs. One might be real time video manipulation for live video conferencing. You can get your feet wet by developing for iPad, or ARM Linux.