IPv6 is the next generation Internet Protocol. In the not so distant future there will be plenty of IPv6-only hosts in cloud or mobile environments.

Currently if you install Ubuntu on an IPv6-only server you run into troubles with the default settings because for instance you cannot reach the security.ubuntu.com mirror or use do-release-upgrade. 

When we collect enough signatures we might be able to convince Canonical to put IPv6 higher on the todo-list!

If Canonical were to support IPv6 in a similar matter as the Debian project does, our lives would be much easier. IPv6 - the future is now!