Two Pokemon events are currently running, to get the two most powerful Pokemon in existence, Mewtwo and Arceus!
Mewtwo is available over Nintendo WFC and knows an exclusive event-only move, Electro Ball. The other moves it knows are Psystrike, Shadow Ball and Aura Sphere. Runs until March 6th so get it asap.
Arceus is available as the result of the Befriend-a-Pokemon
vote last year. It is received via the Pokemon Global Link - visit pokemon-gl.com, go to the Promotions page, click on the Arceus event and enter the password ARCEUSVOTE. Then just use game sync to bring it to your game. The Arceus has the moves: Recover, Hyper Beam, Perish Song and Judgment. Event runs until May 1st.
Finally, there has been some suggestion of a possible new game announcement. Junichi Masuda (one of the directors at Game Freak) said there will be an announcement in the next episode of Pokemon Smash in Japan this weekend. Whether this will be the companion game to Black & White (commonly referred to as Gray
), Ruby/Sapphire remakes, or a completely different game remains to be seen. We'll post news as soon as we get it.