The Secret Is Out on Super-Secret Bases!
Create and hang out in your own Super-Secret Base in Pokémon Omega Ruby and Pokémon Alpha Sapphire!
Super-Secret Bases are an awesome new way to express your creativity and join up with friends in the upcoming Pokémon Omega Ruby and Alpha Sapphire games. Create a Secret Base that’s all your own, including selecting and placing Decorations however you like. You can use Decorations to create tricks in your Secret Base, decide the rules for what kind of Pokémon battles are allowed there, and make it like your very own Pokémon Gym! Then get ready for other players to come and challenge you!
Pokemon.com confirmed super secret bases
Youtube vid with screenshots and other minor information
There are some rumors going around that there will be a Mega Flygon. Aurune, the super secret base expert, has a Flygon and a Flygon only. In the screenshots of him, there were no keystones on his sprite, but Korinna didn't have a keystone in sight either, but she revealed it after you beat her gym.
Oh, and WTF is the-
and make it like your very own Pokemon Gym!