The upcoming PSP version of the game will have some significant changes, like this new opening intro sequence and new song done by Shuhei Kita (the same performer behind Persona: Trinity Soul's intro). In addition to being able to take control of a female lead, the gameplay has also been tweaked with brand new Beginner and Maniac modes. Players will also be able to move to any location they want from the menu -- a much improved experience for handheld play. Finally, you'll be able to issue commands to square mates directly, a pretty significant change from the original PS2 game.
All in all, we have to say we're very excited for Persona 3 Portable. Now, we just need Atlus to get working on an English version ASAP!
*Shooting yourself in the head is not awesome. Do not attempt at home. Persona 3 is a video game, and real-life results may differ. Please consult a physician before shooting yourself in the head.