I copied this from serebii.net
Nintendo has announced that, as of May 20th 2014, all online services across the DS and Wii games will terminate. This means that you will not be able to go online with any of the following Pokémon games: Pokémon Diamond, Pokémon Pearl, Pokémon Platinum, Pokémon HeartGold, Pokémon SoulSilver, Pokémon Battle Revolution, Pokémon Black, Pokémon White, Pokémon Black 2, Pokémon White 2, My Pokémon Ranch, Pokemon Mystery Dungeon: Explorers of Time, Pokemon Mystery Dungeon: Explorers of Darkness, Pokemon Mystery Dungeon: Explorers of Sky, Pokemon Ranger: Guardian Signs, Pokemon Ranger: Shadows of Almia & Pokémon Conquest. All online features of these games will be inaccessible, regardless of the console you play them on. All 3DS and Wii U games will continue to be playable online