Hm... I don't think anyone's mentioned Mega Aggron yet, which is quite probably my favourite Mega Evolution in terms of looks alone. I'm still looking for information on its stats (And hoping for a Special Defense buff), but from what we know now, Aggron's already received a pretty excellent Mega Evolution. Loss of a Surf/Scald weakness and 4x weakness to Fighting and Ground is obviously great, although Mega Aggron isn't going to like taking Fire Blasts etc. from special attackers. Filter is much more useful without the double weaknesses, though. I'm not sure how much speculation this thread allows, but considering Aggron's off-balance stats right now, I'm guessing a small increase to Attack, Defense, and Speed, and a large one to the other defenses.
Oh, wait, just remembered that Filter overrides other abilities. I guess you could use or bluff Rock Head + STAB Head Smash before you Mega Evolved, but Sturdy probably won't see as much use anymore, and after the evolution Head Smash wouldn't be a very useful moveslot. Hm.
I would like to ask everyone what are your impressions of CharizardX and CharizardY? Which one is better? Do u think drought being only 5 turns now tilts the balance in favour of zardX? And do Ground attacks affect zardX (I am asking cause zardX clearly has wings)?
Well, we know the X evo doesn't have Levitate, and it seems unlikely that intrinsic immunities would have been implemented without anyone noticing, so I doubt it still keeps its Ground immunity. Judging by looks alone, anyway, its wings don't look outstandingly flightworthy (Although apparently it still flies in its animation? Bleh). Still, good STAB combination and no weakness to Fairy and Ice helps, and as someone already said, Dragon Dance + Tough Claws sounds outstanding. As for the Y evolution, the nerf to weather abilities and the inability to hold Heat Rock will mean that it'll have to switch out more often if its team wants the sun to stay up and doesn't have Ninetales. Meanwhile, Stealth Rock remains broken (yes), and switching will really, really not have a good effect on Charizard Y, so it won't get more than one chance to sweep or support without Leftovers and a bit of luck. Worth noting though is that Charizard X is probably no longer immune to (Toxic) Spikes and has a single weakness to Stealth Rock, so it won't particularly like switching either.