Even if you have already played the original, in Japanese or through a fan translation, this one offers new content in the form of new sidequests, a new interface, and an optional new soundtrack by director Shoji Meguro. This post also offers new content: screens in the gallery below, and a trailer after the break.
Persona 2: Innocent Sin was the first game in Atlus's Shin Megami Tensei series to drop the traditional first-person dungeons in favor of a third-person viewpoint. Like the other Personas, it's all about cool high school kids negotiating (and fighting) with demons and discovering their powerful "Persona" alter egos. In this one, students at Seven Sisters High School find that rumors start mysteriously coming true in their hometown of Sumaru City, including the rumor that if you call your own cell phone number, a demon called the Joker appears and grants a wish. Being teenagers, the kids decide to wisely avoid tempting fate.