In our ongoing process of getting the NTP Pool IPv6 compatible we took a first (small!) step getting the website partially available via IPv6. For now it's via an IPv6-only hostname: www6.ntppool.org.
So far the anecdotal reports are that it's working fine for people with IPv6. The next tests will be to see how connectivity is affected for everyone else if a host has both AAAA (IPv6) and A (IPv4) records in DNS.
As part of the same change, the website is now served through Varnish which makes it a bit faster and more importantly makes it inconsequential when people rudely try to "sync time" via HTTP to the server.