A sequel for Persona 4 Arena was test earlier this. For those who don’t know Arena acts as verses series for Atlus putting their favorite rpg Persona in the fighting ring putting character from so far Persona 3 and 4 against each other. This time the old crew is coming back with some new moves and new options such as the choice between normal and shadow type which has you play as the character shadow double ganger who can fill up their sp bar quicker. Two new characters have been announced so far. Yukari Takeba and Junpei Iori from Persona 3 join the fray bring their skills honed from the last time they entered the other world. The game acts like a bridge story wise linking Persona 3 to Persona 4. Last time around it was through the someone taking control of labrys this time it can be anything. The link below we send you over to Siliconera who give a deep tutorial of what has changed for basic commands. As for the new changes you will have to stick around to find that out.
Article:http://www.siliconera.com/2013/08/16/new-persona-4-arena-introduces-shadow-type-characters-and-more/
Update
The game is an arcade only update with at the moment no console release. The reason why people are thinking it is a sequel is because their is a lot of content added to the game just for an update. If there are any changes I will let you know.
Update to the article :
http://www.joystiq.com/2013/08/16/persona-4-arena-arcade-only-update-adds-new-fighters-moves-sys/
As always thank you.