I can't speak for Verizon, but in Canada I know we're looking at Carrier grade NAT since Cellular is requiring additional IP space and is still a massive growth

I can't speak for Verizon, but in Canada I know we're looking at Carrier grade NAT since Cellular is requiring additional IP space and is still a massive growth area. We already use NAT for cellular users, but as the network grows, public IP space is still needed for network equipment, for the NAT gateways, etc.