Why do that when you can use Intel's x86 SoC? Or even AMD's. This year...
The presumed Apple SoC wouldn't be x86 based, it would be ARM based.
Intel has previously said that power efficiency is one of its top priorities in chip design going forward.
They've been saying this for at least the past decade. The don't have a reasonable low power offering to compete with the likes of ARM, but they know people are a reluctant to leave x86, so if they can keep claiming that a lower power x86 is right around the corner, people will wait one more generation at a time...
I think we're due to see a major realignment in the PC market. People are realizing they don't need 16 3GHz cores to check their email, but they'd like something light and low power. iPad finally broke open a tablet market that Android helped fill out. Intel and Microsoft are pushing their own platforms now, competing with their own customers, hoping to retain as much of their legacy market as possible.
They might describe these as "concepts", or "platforms", but if they aren't trusting their customers to be able to design to their own markets, then it looks like the start of the blame game. Of course the problem from their perspective isn't that x86 can't modernize, or that Windows is badly bloated, but that Toshiba can't design.
Something's got to give.
While I'm looking forward to seeing how this shakes out, my concern is that I do need 16 3GHz cores at times, and I'm starting to worry that it's going to become more difficult to do serious work in a market aimed at Facebook checkins...