I think you're close.

The only PC of the future I can see is what would be considered an embedded system of some description at the moment; not a re-purposed one but one that is designed to be used for something else.

I don't see ARM or Intel getting a look in here as they are not open architectures. ARM is almost always in a notoriously unknown licensing status from experience.

I reckon that the market will divide into consumption, some open architecture that doesn't exist yet (for power users, enthusiasts running Linux) and this sector which is hacking devices.

The PC of the future doesn't exist. Yet.