More new Mega Evolutions revealed, courtesy of Corocoro magazine via Serebii.net:
Mega Pidgeot is Normal/Flying-type with the ability No Guard and Mega Beedrill is Bug/Poison-type with the ability Adaptability. Latios is exclusive to Omega Ruby, and Latias is exclusive to Alpha Sapphire. Also, all legendaries can only be found on islands in the sky, accessible via Mega Latios and Mega Latias using the Eon Flute item.
Wow, this makes me happy. Pidgeot was my next wanted mega evolution right behind Dragonite and Lapras.