Persona 4: The Ultimate in Mayonaka Arena (what a mouthfull) is an upcoming Persona fighter developed by Arc System Works, the folks behind BlazBlue. Check out the opening sequence from the game above.
The game is set two months after the events of Persona 4. The game will see an Arcade release in Japan this March with a console release in the summer. No word yet on an international release.
Thanks to Siliconera for the info.