It's not going to play out like HTML5. There was no real urgency to replace HTML4, so we could wait until something better than XHTML came along. The IPv4 add

It's not going to play out like HTML5. There was no real urgency to replace HTML4, so we could wait until something better than XHTML came along. The IPv4 address shortage is urgent, so we're going to have to use one of solutions available now, which is either IPv6 or carrier-grade NAT. IPv6 may have its flaws, but carrier-grade NAT is far worse. While an ordinary user might not see the difference, website operators certainly will, since carrier-grade NAT makes it impossible to track and block abuse (without substantial collateral damage). I imagine that HN uses IP addresses extensively for bans and voting-ring detection. Already, some ISPs (e.g. T-Mobile) are giving users public IPv6 addresses and private IPv4 addresses that are NAT'd. In order to distinguish between different users of these ISPs, HN would need to support IPv6. Other ISPs are worse and are just doing carrier grade NAT without IPv6 (mainly in Europe/Asia, though Verizon has announced they will start doing this to some of their DSL customers in the US). For these users, HN supporting IPv6 would do no good, except to show to these ISPs that there is a point to them deploying IPv6. (Yes, one site is just a drop in the ocean, but if everyone did their part and adopted IPv6...)