There have been media rumors circulating around for a little while that NZ might not get the business for the next three films. This was definitively debunked and put to rest on December 15th. See this article in Variety for more details.
Also, here’s a short video of the New Zealand Herald’s coverage of the actual announcement by New Zealand’s Prime Minister, John Key, with some comments by James Cameron himself. Jon Landau of Lightstorm Entertainment and Paul Hanneman from 20th Century Fox are also in attendance:
Update (July 29, 2013): AvatarMeet 2013 is now in the history books, but the memories and the new and renewed friendships are still fresh in the minds of all who attended. From all of us at LearnNavi, a huge irayo! (thank you!) to the event planners, Dr. Paul Frommer, the great folks at Lightstorm Entertainment and all who supported this year’s meetup!
Unsurprisingly, a 2014 AvatarMeet is already on the minds of the organizers, so keep an eye on the AvatarMeet website for info about next year as it becomes available!