Well, for the core recurring handler, not much more will be done. It's meant to be basic and mostly is there as a proof-of-concept. All that's really lacking is some solid documentation I can point folks to that says as much. For a more full-featured solution, you're going to have to get your hands dirty in the code. A lot of this is due to the fact that every payment gateway's API for recurring fees will be different. So, the recurring module handles setting up recurring fees on the product level, but you should code your own recurring fee handler that works with your payment gateway to have the best solution.