Last night a new legendary (illusionary) Pokémon has been revealed through the Pokémon Sunday tv-show, and thanks to the official series site, we have quality images of it.
Behold, Victini* [ビクティニ]; actually the tiny critter that was shown at the end of the 14th movie trailer. It is number #000 in the Isshu Pokédex and the first Generation V legendary to be distributed via Wi-Fi. During September 18th and October 18th, players will be able to download the Liberty Ticket [リバティチケット], which will allow them to meet the elusive Victini.
* Typically romanized, it reads Bikutini, but it appears that the victini.com domain has been registered on behalf of Nintendo by a usual third party.