Re: x86 is still valuable but long in the tooth
Indeed, there's a lot of competitors on the scene now. ARM is a big on as you said, though AMD could also weigh in as it's shown some real dominance in the small form factor PC markets.
Nvidia has some real powerhouse chips too, though they're being put into vehicles rather than wearables at the moment. However its Tegra line is powering high end smartphones and tablets, so there's no reason the next version coulldn't have a wearable iteration.
And then of course there's Qualcomm to watch out for.
Intel might have lofty goals, but the chip and SOC manufacturing space is much more crowded than it used to be.