Re: The simple way to avoid this..
IMHO, it will be the Carriers/Networks that would be against this. If Apple and whoever is next to implement this asks the Carriers to let them use this in country X and the carriers say no then how much bad publicity would that be for that Carrier.
I see this as making the gouging from roaming largely a thing of the past except in places like India where you have to hand over the soul of your firstborn to ger a SIM.
I am just surprised that it has taken until now for it to happen.