With the upcoming release of Skyward Sword Nintendo has announced that it will not feature a left handed mode.  This wasn't an issue with the previous Wii Zelda, Twilight Princess in which the game tolerated less careful gestures with a more limited and less interesting move-set as a result.  Without a lefty mode, Link will keep his sword in his right and the player will have to decide which hand to put the Remote in and which will wield the Nunchuk.  Skyward Sword will be released on on November 20, 2011.

Source: Kotaku