[Update: This announcement is an official Nintendo reveal of the new event Pokemon; however, Meloetta was already known to exist in the original Black and White due to a 2010 hack. It is currently unknown if she'll be coming to Black 2 and White 2, but she will be starring in her own animated short, Meloetta's Sparkling Recital.]
Nintendo has officially unveiled the latest Pokemon to join the 'Dex, a Powerpuff Girl! OK, no, it's Meloetta, a genderless Melody Pokemon first spotted on the poster for Pokemon the Movie 15 last week. So far Meloetta is the third new Pokemon revealed recently, right behind Keldeo and Black Kyurem and White Kyurem. With its addition, the Pokedex has now reached 648 entries.
Pokemon Black 2 and White 2 are set for a fall release in NA and Europe.