Atlus revealed a trailer for this new entry in the SMT series and there are images already leaked about the game. According to the trailer the game's release is set for 2013 and not much else is said about the game as far as part of the game will take place in a Tokyo district (Ginza) and it will have voice acting and cutscenes. If you want any more info here are some site references, enjoy.

Screenshots of the game.
Shin Megami Tensei IV Trailer Images Leak Out Onto The Net | Siliconera

Game Trailer.
Shin Megami Tensei IV coming to 3DS in 2013, here's its debut trailer | Joystiq

SMTIV Overview.
Shin Megami Tensei IV (video game)