Mega Beedrill, Mega Pidgeot and Mega Latias/Latios revealed by CoroCoro

New Pokémon Mega Evolutions have been revealed in the October edition of CoroCoro! These are Mega Beedrill and Mega Pidgeot, plus Mega Latias and Mega Latios that were found in the game code of X/Y are officially confirmed.

Mega Beedrill and Mega Pidgeot

Mega Beedrill remains Bug/Poison but gains the ability Adaptability.
Mega Pidgeot remains Normal//Flying but gains the ability No Guard.

Mega Latias (left) and Mega Latios (right)

Type/ability details for Mega Latias/Latios have not yet been confirmed. They can be befriended in-game using the Eon Flute item, after which they can fly you around and find new Mythical Places on islands or in the clouds. These Mythical Places each hold different legendary Pokémon. Even non-event legendary Pokémon can supposedly be found in ORAS.

Latias is exclusive to Alpha Sapphire while Latios is exclusive to Omega Ruby, however there will also be an event to obtain the Eon Ticket, allowing access to the other one.