I was expecting IPv4 to be around forever, for similar reasons that COBOL and the still emulated 8254 PC beep are: there's too much critical infrastructure using it.
Honestly, when could we ever retire IPv4? We've had, what three or four decades now, of building the world's infrastructure on it. What's a realistic scenario to retire that stuff even if everyone gets on IPv6 in 10 years. Another 50 years? 100? 500?
Our great-great-grandkids will still be troubleshooting the 'hey who deleted localhost from /etc/hosts' problem.
