Meganette is pretty much the coolest thing ever.
This is from bulbagarden: "9. The power-up of Mega-Evolved Pokemon is meant to elevate them to the class of legendary Pok?mon, hence the restriction of only one Pok?mon being allowed to hold a Mega Stone during battles." It's pretty much what it looks like. Hence why ALL of the megamons get OP stats - even those who had below 500 BST beforehand, which means more than 100 BST buffs.
It seems gamefreak focused on the new generation and a select few old mons when making this game:
"6. When distributing new moves and abilities, priority was given to new Pok?mon."
"8. The standard selection process for Pok?mon to be Mega-Evolvable is based on three points: visual looks, popularity and game balance."
And, to be honest, I'm thankful for it. It means the metagame won't be stupidly diverse. I'm all for a smaller selection of threats to take into account.
Mat Block | Fighting | Other | - | - | 10 | Using a pulled-up mat as a shield, the user protects itself and its allies from damaging moves. This does not stop status moves.
This is a cool move for Doubles. It's a partywide Protect that doesn't work for support moves.
Frost Breath | Ice | Special | 60 | 90 | 10 | The user blows its cold breath on the target. This attack always results in a critical hit.
Now more powerful than Blizzard as it virtually has
the samehigher base power and higher accuracy and PP. It also ignores SpD buffs because it crits.
EDIT
http://www.serebii.net/xy/temp/00540.png