its a step backwards!
i have a phone here in the uk thats an old one, it never had a sim it was locked on the network, i think its a motorola locked to vodafone uk. no slot or anything for sim only battery, its a green screen on it and, it still works and fits in your pocket. this came out before the sim card's they could not be unlocked or switched to other network.
if they go ahead with this its a step backwards.