DaveB: The blocking is certainly making news elsewhere. Here is an article (Slingshot mentioned as well).
http://www.engadget.com/2015/01/03/netflix-clamps-down-on-vpns/
From Engadget article.
Update: Netflix tells us that there's been "no change" in the way it handles VPNs, so you shouldn't have to worry about the company getting tough any time soon. With that said, these blocking errors started showing up in the past few weeks, so it's not clear what would have prompted them.
So really no news.. I feel you can't really block VPNs permently but Netflix could block DNS services by always checking the IP address of the Netflix user for all requests.