We probably won't see widespread use of IPv6 before 2020. It will take everyone a long time to switch.
Few ISPs and other organizations are even routing IPv6 traffic. (I know mine doesn't).
Because of this IPv6 traffic will get nowhere on the internet at this point.
(There used to be something called the 6bone which was an IPv6 test network, where people with fast servers could 'link up' to it, the traffic was IPv6 tunneled in IPv4. This has been disbanded I believe).
Also, even in Windows XP, IPv6 drivers are not installed by default.. You have to go add a new protocol and find the "IPv6 developer driver" or whatever it's called.
But yes, apps that only understand IPv4 should still work. Their traffic is tunneled thru IPv6, and the IPv4 address that the program sees / expects is really part of an IPv6 address (with some special bits to tell the system that it's a 6-to-4 tunneling address)
Programs like these already exist. There may even be kernel drivers in the works / written already that will do this.
However, by 2020, I'm certain OP2 will be rewritten and support IPv6 natively. (Well, I *want* to rewrite OP2 sometime).
