Ok, so I was just browsing the official site today and noticed that there was an update with something that appeared to be a Japanese release date.
I'll be honest, I can't read Japanese, however it appears that (from the google translation) the release date for this game is/could be the 26th of December.
The translation also mentioned things about a special edition of the game ("Illusion Revelations #FE Fortissimo Edition") that comes with an "outer box" illustrated by toi8, an official art book and a CD with six songs on it.
There is a definitive edition wii u as well.
Also there was this picture included with the update (could somebody please translate it).
Character DLC costumes:
L -> R: Touma (Walter SMT IV)/Itsuki (Devil Survivor 2)/ Tsubasa (Person Q) / Tsubasa or Kiriya (Etrian Odyssey III)
My friend also just sent me this for anyone that is curious about the sample box art.
They end with saying that there will be more information in October.
(If there are any inconsistencies with this post please notify me so that I can change it accordingly).
Edits [09/11/2015] - DLC costumes for characters added.