First off, last week Mega Pidgeot and Mega Beedrill were leaked, however I waited to post on them as I felt we would be likely getting more as the Demo started to be released. Mega Pidgeot gets a boost to Sp. Attack and the No Guard ability. Mega Beedrill gets a boost to Attack and Speed, and gets Adaptability as it's ability.
Finally, the code to download the US Demo has been confirmed to be released through the Trainer Club's October News letter. If you haven't already signed up for an account on Pokémon.com, I would suggest you do so quickly!
UPDATE: Mega Glalie has been confirmed as a pure Ice type with the ability Refrigerate.