Here's the official statement by Atlus,
"The 'Persona 4 Arena Arranged Soundtrack' disc, a set of select songs derived from the game's score," Atlus said. "With stage themes based on the music of Shoji Meguro, the acclaimed composer of countless award-winning Shin Megami Tensei and Persona titles, the Persona 4 Arena soundtrack is as memorable and gripping as the action that unfolds in the Midnight Arena."
So yeah pre-order Persona 4 Arena and get the soundtrack(which is a CD and not a download code).
Persona 4 Arena comes out on August 7th for Xbox 360 and PS3.