IPv6 Progression

So since IPv4 can't be here forever and the number of IPs is bigger and bigger, sooner or later i suppose many will have to switch to IPv6 , or all if coexistance gets removed. So what do you think how much time since the change becomes noticable and a question for experts - how will that affect network security and hacking. I am interested will the laws of IPv4 network dramatically change that it would require a new understanding of IPv6 to keep up with time (Packet structure, connections, handshakes,dns, dhcp...?). Thank you!