More info than you'll probably need until July's launch
We're all excited to play the newest main series entry in the Shin Megami Tensei series, but that day is still a few months away. For now, we'll have to deal with more info on Shin Megami Tensei IV, compliments of Atlus' NicoNico Super Meeting 2 Q&A session.
Firstly, we now know that there are no direct connections between SMT IV and the other numbered games in the series (I, II, and Nocturne), or Strange Journey (outside of a possible connection with the Black Samurai). It'll take "at least" 50 hours to complete the game, if not "60-100" stated some developers. Paid DLC was also confirmed, as was the ability to turn off voicework, a harder difficulty mode, and other semi-spoiler related facts that you can read here.
Another interesting tidbit is the fact that the developers stated the Shin Megami Tensei series was "better suited for male leads," after a fan asked if there would be a female option for SMT IV (kind of like Persona 3 Portable). Although the option wasn't ruled out entirely, it seems as if they aren't currently planning on it. It would be interesting to get some clarification on why the series is better suited for male leads, as something is most likely lost in translation there.
Shin Megami Tensei IV [Siliconera]