Is it possible to get a list of all the layers served by geoserver? I.e. is there some specific url request to send that does this?
The capabilities links on the geoserver home page each list layers served via various services:
A sample WMS request would look like this:
http://demo.opengeo.org/geoserver/wms?request=GetCapabilities&service=WMS&version=1.0.0