In an web application that needs to have some kind of modularity, having one single configuration file for Flex Services will enforce each module to register it's destination in this configuration file. Although I don't know if it's possible in Flex DS, I guess that it will be nice to have this kind of feature in GDS.

I imagine three different solutions, not all of them being so nice:
1. Provide an annotation for classes that want to be exposed as destinations. Using a Spring BeanFactoryPostProcessor, on can easily discover all beans inside application context that have this annotation and automatically register those beans as GDS destinations.

2. Create a FactoryBean for Destination's to be used inside an application context that will instantiate destinations and register them inside ServicesConfig under the specified Service.

3. Use custom namespaces inside spring configuration files. Need to create an XSD for destination elements and other configuration options specific to GDS. I have noticed that is very easy to transform a org.w3c Dom document into a JDOM document so no need to change granite config classes.

I have started to implement something and would be more then happy to contribute patches but I like to hear first from you what do you think.