I don’t know that much about IPv6, but it sounds good, if it’s possible. How ever, keep in mind that as of now, 9/10th of the world still uses IPv4! So it is a great idea, and developer(s) (how much does bitcoin have anyways?) should implement it in bitcoin (in my humbly opinion). How ever, making it default to use IPv6 isn’t a good idea.
It’s totally viable when everyone will be using IPv6, it’s just everyone still uses IPv4!
(And I see now that in my previous post I basically explained what other people adviced… Oops!)