Gamestop have recently revealed their pre-order bonus offering for those who pre-order Fire Emblem Fates. The items themselves are three character keychains depicting Marx/Xander, Ryouma, and Aqua/Azure. You get all three for pre-order either Conquest or Birthright, not sure about the Special Edition though it’s most likely the same case.
Fire Emblem Fates is a Nintendo 3DS exclusive and will be released on February 19th of this year.