My understanding is that HGV driver was removed from the NZ national skills shortage list back in about February 2014.
However, Canterbury has put HGV driver on their regional critical shortage list because they still have a lot of cleaning up and rebuilding to do after the earthquakes. Note, though, that I don’t think the Canterbury visa would lead to eligibility for permanent residency, it will only ever be temporary.
I am no expert, I may have got it wrong, but that is my current understanding. I remain hopeful that the NZ government might return HGV driver to their shortage list at some stage, as I am still seeing reports that their trucking industry is in trouble and local recruitment is not working to deliver enough drivers as the government intended.