From Bulbanews, your community Pokémon newspaper.
Available at nearly 1000 locations
The Eon Ticket, an item which allows Trainers to go to Southern Island in Pokémon Omega Ruby and Alpha Sapphire, will be available at nearly 1000 Play! Pokémon Leagues across the United States. Since Eon Tickets can be shared via StreetPass, the intention is for these players to spread their tickets in this way. It is unclear how many codes will be available at each location.
When visiting Southern Island, the player can obtain Latias in Omega Ruby or Latios in Alpha Sapphire, the member of the Eon duo not normally available in that game.
The official site recommends players visit Pokémon events and tournaments in order to obtain the Eon Ticket.