According to a recent interview with Shigeru Miyamoto, players will be able to insert a Gamecube memory card with Animal Crossing or Dobutsu no Mori saved data on, and transfer their catalogue and character on top of being able to import villagers to their City Folk town.
I was gonna get this game with a GameStop gift card, but I didn't know I was gonna get it via regular mail and not e-mail. The gift card won't come until next month, so I have to wait until I get paid to get the game.