POKEMON GEN 6 ANNOUNCED

[NICKtendo DS]

I just checked the latest screens on Serebii and noticed Blazikenite and Lucarionite for example are Mega Stones. That's what confused me. How it was written earlier on Serebii, it was as if Blazikenite and Mega Stone were seperate items.
I was hoping you had to use an item in battle rather than have the Pokémon hold it and it'll evolve before the battle starts. Still, you'll sacrifice an item slot to evolve, but I'm not seeing the strategic value in this as the Mega Stones are most likely superior to any item you can attach to your Pokémon. It would have been interesting having to use it in-battle, so the player has to think whether it's worth it using a turn to evolve. Could have been an interesting mechanic in Double/Multi Battles too.