I'm hoping in gen X/Y, gamefreak doesn't do the same "exclusive untradeable ultra impossible" legendary bullshit as they have for several generations with Celebi, Mew, Jirachi, Manaphy, Shaymin, Darkrai, Arceus, Victini, Keldeo, Meloetta, Genesect... not sure if I forgot one.
It makes the "catch 'em all" aspect of the game impossible to complete for someone as far-removed from pokemon hubs as me to acquire through these exclusive Nintendo Events. I'm stuck gamesharking my rare pokemon in, and that doesn't sit right with me.