I'd very much like to be proven wrong.
The main issue was indeed as you pointed out to get the power-consumption down and hence battery-life up.
I've been eyeing the 450 cores for a while now and they finally seem to be able to get near the powerconsumption of the X-Scale/StrongArm CPU's which are present in nearly all high-end PDA's.
OS 4 is in no way dependent on the Articia chipset so in theory OS 4 could be made to run on one of these devices.
