Pokemon repository Serebii has the skinny on a couple of new game announcements. The first bit pertains to Omega Ruby & Alpha Sapphire — scans from the Japanese CoroCoro magazine reveal that Metagross will be receiving a Mega evolution in the 3DS remake. Metagross will be used by the trainer Steven Stone, who evolves his Pokemon using the Mega Brooch item. Also in the scan are suggestions that different Pokemon will populate Hoenn than in the original Ruby & Sapphire.
The second piece concerns UK Pokemon X & Y players — from July 11 to August 10, you can visit a GAME location and download a special Charizard that comes with a Charizardite Mega Stone from the opposite game. In other words, if you own Pokemon X, you'll be able to obtain Charizard's Mega evolution from Pokemon Y, and vice versa. Hopefully this event comes to the US soon.
As for Omega Ruby & Alpha Sapphire, it's still on track for a November 21 release on 3DS.
