Nintendo have announced a new pair of games for 3DS, to be released November 2014. They are remakes of the third-generation games Pokémon Ruby and Pokémon Sapphire which were released in 2003.
These games are titled Pokémon Omega Ruby and Pokémon Alpha Sapphire. The box art, which can be seen below, features Groudon and Kyogre like the original games, however they look a little different - note the symbols for the Greek letters Omega (Ω) and Alpha (α) highlighted in their designs. This is a strong hint that the two Pokémon will gain a new form or Mega Evolution (of course this is not yet confirmed).
An announcement trailer (see below) was posted by Nintendo, and then earlier today Japanese show Pokémon Get*TV previewed a tiny snippet of footage, showing the awakenings of Groudon and Kyogre.