What will become possible?

More robust and scalable network
NAT is a single point of failure
NAT limits scalability
Any device can be connected to the net
cellphones, microwave oven, watch, motorcycles, ...
with IPv4 it was not possible due to address shortage
Helps new technology/application deployment
NAT has been preventing new protocol deployment
IPv6 has more recent technology by default
autoconfiguration, IPsec, multicast, ...