You can play as Robin in Batman: Arkham City.
He's playable in two Challenge maps, according to Game Informer - but only to people who purchase the game at Best Buy. And Best Buy is only available to people in the US.
Robin is one of Warner Bros.' shop-specific enticements. What they'll be here in Europe we don't know.
Batman affiliate Catwoman plays a more central role in Arkham City, however. She even has her own spin-off missions.