During the closing ceremonies of the Pokémon World Championships 2013, a new trailer featuring Mega Pokémon was first revealed. It was also revealed that Washington D.C. will be the location of the 2014 Pokémon World Championships.

Mega Pokémon Trailer

Pokémon World Champions 2013:

Pokémon Video Game Junior Division: Brendan Zheng (USA)
Pokémon Video Game Senior Division: Hayden McTavish (USA)
Pokémon Video Game Masters Division: Arash Ommati (Italy)
Pokémon TCG Junior Division: Ondrej Kujal (Czech Republic)
Pokémon TCG Senior Division: Kaiwen Cabbabe (Australia)
Pokémon TCG Masters Division: Jason Klaczynski (USA)

Source: http://www.pokemonworldchampionships.com/2013/updates/article/day3/thats-all-from-vancouver