An application named MONSTER HUNTER 3 ULTIMATE Packet Relay Tools for Nintendo 3DS will be made available as a free download on the Nintendo eShop on Wii U.
This application allows players of Monster Hunter 3 Ultimate on Nintendo 3DS to play the game online by using a Wii U console connected to the Internet via the Wii LAN Adapter or Wii U LAN Adapter (to be sold separately). Using this set-up, one Nintendo 3DS system can connect to the Wii U console, and play Monster Hunter 3 Ultimate online with other players.
Well, what I'm insterested to know is cross-region compatibility in specific with Japan and Asia. I know EU and NA are basically cross compatible already, but they didn't mention the Asia counterparts.