Well obviously, this being Etrian Odyssey, there has to be secret classes, right? We now have a new 'Warrior' class, but this is more unique than before. See my avatar? It's an entirely new species, rather than just a class.
Did I say classes? The first has already been revealed as the Mystic. Looks elven.
And, as the title says, Subclassing is making a return.
Famitsu page. Untranslated info about the new features. Later on, you can see alternate colors making a return.
All below images come from Famitsu, pretty much.
Gamefaqs post with all the missed information on the first secret class, Mystic.
Mystics are a more magic oriented class, while the warrior, obviously, is melee based, probably something like a brawler going by the club on one male and giant sword on the other, to shogun/ ronin with the katanas on the females.