This tournament features a rather drastic change from the previous tournaments, with all Pokémon legal for use (except for Chatot) and with each battle using the Rotation Battle format. This means Pokémon such as Arceus, Darkrai, Keldeo, and even Genesect are allowed in your team. The Soul Dew item and the moves Sky Drop and Dark Void are all banned.
Registration is open on the Pokémon Global Link from February 7th (00:00 UTC) until February 14th (23:59 UTC). You will need a Pokémon Global Link account as well as either Pokémon Black 2 or Pokémon White 2 that has Game Synced with your online account, as with any Pokémon Global Link tournament. Registration is open to the first 50,000 entrants, so make sure you register early if you want to be guaranteed a chance to play!
The tournament will take place from February 15th (00:00 UTC) until February 18th (23:59 UTC) online. Full instructions can be found on the official tournament page. Everyone that participates in at least one battle with a win or loss result will receive a Micle Berry after the tournament concludes. This interesting berry is consumed when the user's HP falls low and it then raises the accuracy of the next move the user uses by 20%.
This is a great chance to battle against players from all around the world and in a different format than usual, so you should definitely check it out!