An extended version of Persona 3 has been released, but it seems that it isn't only a small update, but it has some major changes.

Quote Originally Posted by Game Informer
Just playing through the opening sequence of this game again sends shivers down my spine. Persona 3 was one of the best RPGs of 2007, and if you missed it the first time around, this is your chance to make amends. However, FES isn’t only about bringing in a new audience. In true Atlus style, the game also services hardcore fans with a number of great enhancements. Cool additional content to the main story (like new personas to obsess over) is just the beginning; the real draw for veterans is the entire epilogue chapter that is almost a full-sized game itself. Aigis is awesome as the protagonist for this segment, though I was a bit disappointed to see most of the school simulation aspects fall away in favor of a purer dungeon-delving experience. It makes sense for the story, but the academic and social elements are highlights in the base game, so it’s weird to lose them. Thankfully, the original adventure is included in its entirety, making Persona 3: FES more than just an expansion pack. With a mere $30 price tag, it’s the perfect way for fans and newcomers to experience this exceptional RPG.
For even more information, the Wiki entry can be found here.