Many people over the past few weeks have been working hard to find ways to dump information from Pokémon X and Y. Recently people like Smealum
, Xfr from Pokécheck and Bond697 from ProjectPokémon have discovered and begun to document information previously unavailable from these games. Three new Pokémon who's names are Diancie (#719), Volcanion (#720) and Hoopa (#721) as well Latios and Latias Mega Evolutions were uncovered. AZ's Floette was also revealed as well as two more color variants of Vivillion.
None of these Pokémon have been officially revealed but The Pokémon Company told Kotaku
that they have "nothing to report at this time." It is unknown when these Pokémon will officially become available to players of Pokémon X and Y but if previous generations is any indication, it could be a long time from now.