Animal Crossing: New Leaf's LTD was revealed to be 2.73 million.
Since the game is only available in Japan so far, we're able to check that number against both weekly Japanese sales trackers, Media Create and Famitsu.
Animal Crossing is available as a retail release, via a download card, or via the eShop.
Media Create is confirmed to track only the retail version of titles.
Famitsu is confirmed to track the retail and download card versions.
Animal Crossing New Leaf's LTD via Media Create (as of Dec. 30th, 2012): 1,969,955
Animal Crossing New Leaf's LTD via Famitsu (as of Dec. 30th, 2012): 2,286,977
Simple extrapolation lets us see that AC:NL has sold nearly 800k digital copies (eShop
http://www.neogaf.com/forum/showthread.php?t=510716
Great numbers for the Animal Crossing series!