New Mega Evolutions revealed in CoroCoro

Japanese magazine CoroCoro has revealed new Mega Evolutions and features from the upcoming Pokémon Omega Ruby and Alpha Sapphire.

Sceptile and Swampert will get Mega Evolutions, so along with Blaziken in X/Y, all the Hoenn starter Pokémon now have one.
Mega Sceptile is Grass/Dragon and has the ability Lightning Rod.
Mega Swampert stays Water/Ground and has the ability Swift Swim.

Mega Sceptile and Mega Swampert

The legendary Pokémon Groudon and Kyogre also gain Mega Evolutions, but they are being presented as a different type of evolutions, translated as Ancient Devolution. The new forms are said to be Prehistoric Pokémon.

Mega Groudon and Mega Kyogre

The legendary Pokémon Diancie will also get a Mega Evolution.

Mega Diancie

It was also confirmed that the Mach Bike and Acro Bike both make a return in Omega Ruby and Alpha Sapphire. Team Magma and Team Aqua return, led by Maxie and Archie respectively as before. Finally, instead of a Mega Ring, a Mega Bracelet is the item that activates Mega Evolutions.