The Zorua Event
In order to obtain Zorua, you must send a Celebi that you recieve from watching the 13th Movie: Phantom Champion Zoroark to Pokémon Black/White from either HeartGold/SoulSilver, Pokémon Platinum or Pokémon Diamond/Pearl.
After having recieved Celebi, you must travel to a location which is not yet known (for more information, look at the screenshot), when you arrive at this location, there will be a man with a Zorua as you can see from the screenshot. Talk to him with your Celebi in the first slot of your party and he will offer Zorua for you to take.
More information is expected to come prior to the games release date.