When it all breaks down, not much has been revealed regarding the battle system of FFVII: Dirge of Cerberus. Based on screenshots from in-game action, there seems to be some sort of level-system, combined with real live combat, mainly concentrated on Vincent's famous revolver. In one specific scan, the weapon is marked with some numbers - perhaps this could mean that there is some kind of weapon level up-system. (However, it most likely has something to do with the amount of ammo left.)
Seeing as Square-Enix is behind all of this, we can most likely expect some sort of mathematical system where the status and level of the character determine the outcome of various actions; for example, strength determines the damage given, defense determines the damage taken. Combine this with intense control of the character, much like Dante in Devil May Cry, and you've got yourself a pretty unique approach to an innovative system of combat.