A press release from Nintendo notes:
Pokémon Omega Ruby and Pokémon Alpha Sapphire are a fresh take on Pokémon Ruby and Pokémon Sapphire, which launched in 2003 and were fan-favourite hits on the Game Boy Advance system. The new titles promise to take players through a dramatic story within a spectacular new world.
According to Polygon, Pokemon Ruby & Sapphire were the top-selling games for the Game Boy Advance, selling about 16 million copies worldwide.
As with the launch of Pokemon X & Y. it appears these two games will see a worldwide release in November, rather than the rest of the territories waiting after the initial Japanese release.
Diehard fans have been pining for a Ruby & Sapphire remake for years, as evidenced at least by this Kotaku article. So far there is no word on how different the “spectacular new world” will look or what the new storyline will entail.