I was re-reading over a document at TechLiberty when I came across this: Does the DIA Internet Filter support IPv6? No. This makes me think that not only will this require either an upgrade (software or hardware), potentially costing the tax payer more money but it could be a contributing factor to the delay of the IPv6 rollout at NZ ISPs.
Thoughts?
Source: http://techliberty.org.nz/issues/internet-filtering/filtering-technical-faq/