Yes, actually. It's not going to be anything over-the-top extravagant, but there will be a battle system. It's intended to be a turn-based system, similar to many classic turn-based RPG's. The menu will most likely sport a traditional four options: Attack, Skills, Items and Run. Obviously everything will be fully customizable and changeable and will directly interact with the database extension.
Keep in mind that any battle system that comes with the extension will be included as part of the RPG kit, and not necessarily the extension, though you might expect a spot in the database that lets you easily modify the basics of the default battle system.
Thanks for asking!