Michelle Ruff provides two of the three voices for the female Avatar, both of which sound more than a little reminiscent of Yukari Takeba.
I Knew It: When Male Morgan was confirmed as the boss of the first Future Past DLC Chapter, some fans theorized that Female Morgan would be the boss of the second chapter. They were right. Even less people were surprised that the third and final Future Past DLC Chapter's boss turned out to be Grima.
Marth Debuted in Smash Bros.: Thanks to the SpotPass optional battles and paid DLC, HEAPS of of characters from FE2, 3/12, 4, 5, and 6 are appearing in English for the first time ever in this game. Marth himself averts this, having previously appeared in Shadow Dragon.
One of Us: If his Twitter is anything to go by, Kaiji Tang, the English voice actor for Owain, is an avid player of the game himself.
Talking to Himself: Insofar as Voice Grunting allows, given doubling up among both casts. Especially notable though with the mother-daughter pairs Sumia and Cynthia and Cordelia and Severa in the respective dubs (Ayano Yamamoto and Julie Ann Taylor respectively).
Some of the fathers and sons can end up talking to themselves if you pair the mothers up appropriately: Lon'qu and Brady, Kellam and Gerome, Gregor and Laurent, or Yarne and Robin (if the right voice option is picked on Robin).