The KieStoreServices interface can be implemented in any way for any type of persistence you can imagine. The JPA persistence is currently the most robust implementation available, but there is also another implementation available on top of Infinispan (http://infinispan.org). Also, any other KieStoreServices implementation could be registered and used directly from the KieServices helper class by just registering the actual implementation through the following code:

ServiceRegistryImpl.getInstance().registerLocator(KieStoreServices.class, new Callable<KieStoreServices>() {
    @Override
    public KieStoreServices call() throws Exception {
        return (KieStoreServices) Class.forName(
                "path.to.my.Impl").newInstance();
    }
});

Let's take a moment to review the Infinispan persistence usage with a small code example.