In Pokemon Black and White, there will be a chance to get a rare pokemon called Victini. It said to lead you to victory. Here is what the site says:
Using the Liberty Pass is the only way you can receive Victini in your game—you won't encounter this awesome Pokémon in the wild. The chance to download the Liberty Pass won't be around long—you can receive it via the Nintendo® Wi-Fi Connection service from March 6th through April 10th. Don't miss this chance—this is the only way you can get the Liberty Pass. Also, you can download the Liberty Pass as soon as you begin playing your new game, but you'll need to reach a certain point in the game before you can use it to catch Victini.