For Pokémon X and Y Sylveon and Mewthree will be coming out. Rumour has it that Sylveon will probably the first of a new introduced type, LOVE TYPE. It may be true because of the colour of it and how it looks. I think that it will evolve by holding a Shiny Stone and Happiness (of course you can't hold happiness).
Now Mewthree. The name I’ve typed isn't confirmed but it would be a pretty obvious name if it is because on the Pokémon website they said it was related to Mewtwo and that also meant Mew. So Mew from MEW and THREE for the number after two, so that is the pretty obvious name and it probably is Psychic type so it is probably normal.
If you have any information on those two Pokémon please send a message on this topic.