Just did a random matchup with someone in Japan on my new 3DS. Not sure what problems other people might be having, but the newer hardware seems to work fine with WPA2.
Will update if I actually have any issues.
The 3DS, unlike the Nintendo DS before it, is region-locked. There are 3 regions: North America, Japan and EU/Australia. So if you buy your 3DS in Australia, you'll need to purchase games from either the EU or Australia as well. Nintendo explained their reasoning in the following statement:
“Nintendo 3DS hardware is available in three versions: Japanese, American and European/Australian,” Nintendo told us in a statement.
“Nintendo has developed different versions of Nintendo 3DS hardware to take into account different languages, age rating requirements and parental control functionality as well as to ensure compliance with local laws in each region. Nintendo 3DS also offers network services specifically tailored for each region.”
It went on: “Additionally we want to ensure the best possible gaming experience for our users and there is the possibility that Nintendo 3DS software sold in one region will not function properly when running on Nintendo 3DS hardware sold in another.”
-Source
Best Answer
Yes. (Source)
Note that EU/AU is the same region (1, 2). So in fact, you answered your own question with the link that says the AU version is not locked :P