When we introduced the concept of a cascaded service and the use of GeoServer as a proxy, we discussed a number of scenarios. One of these scenarios was the use of cascaded services to provide a server with increased capabilities. For example, within your environment, you might have a highly specialized or configured WFS server whose sole purpose is to deliver vector data using transactional WFS and WFS-T. An implementation of TinyOWS (http://mapserver.org/tinyows) will be a good example of this. For example, your specialized WFS server might be in place in order to make a legacy data store available to your enterprise in an open standard.
While there is nothing wrong with having a specialized WFS server within your environment (in many cases it actually makes a lot of sense, particularly if you consider it in the context of SOA), it can be limiting. What if you want to publish the legacy data as a map or make it available to other sites and services as a rendered...
