Or, Apple was about to release a new form factor or new design Mac's. But the CPU's and GPU's needed were either canceled or delayed. So there was nothing to release. So they are waiting...
And I am pretty sure, that there is a roadmap to ARM based Macs.
Agreed, and I would have made a similar point if I wasn't reading this on company time
Having leaped the mental hurdle of iPad's being good enough to be my daily driver in a last couple of weeks, it's obvious to me where Apple's priorities and future are.