I shall make a prediction:
I predict that the newly uncovered 'mega' Hoopa (
http://pokebeach.com/2014/10/mega-hoopa-uncovered-in-oras-demo-stats-for-mega-evolutions ) is not actually mega, but this is just a different forme of it. I think this because with most mega's shinies, they have a colour different to the regular version's shiny. And Hoopa's supposed 'mega's' shiny is the same colour as it's normal shiny. Plus, it keeps the same ability. And it's base stats aren't boosted by a total of 100. And to me, it doesn't really look like a mega. I don't know why.
I made this a wall post so that it has the date underneath it, so you can tell that I said this before it was revealed, so I can say to everyone "Ha, I told you so!". But if this is wrong, it'll look a bit odd.