This entry is an attempt to get more structure in my head and get more feedback and insight from others that hopefully leads to a solution worthwhile implementing.
Sean Gillies left a comment (eaten by the moderation filter) on the first entry and more directions in his blog entry.
I read some of the documents on the ORE site and did not find a solution there yet.

The problem

There are a couple of aspects that I need to write down to explain the problem faced when working on a general solution for linking OGC services in news feeds.

OGC Services in practice

OGC services allow clients (users or better, applications) to construct a URL with some variables and get something in return; A map graphic for instance from a Web Map Service. The workflow on such service has been designed so that the client first does a GetCapabilities, parses that document and starts interacting with the service to actually get something done. Drawing a map for instance, identify an object, interrogate a catalog and so on and so forth. I will stick to Web Map Services in this blog and may thus miss the ball when it comes to other OGC services ;)

Today I finished some work on the RSS output of GeoNetwork opensource that should allow people to search a metadata catalog for OGC web map services, KML, data for download and whatever else someone decided to publish in ISO19115 formatted metadata.

Providing a search interface with an RSS output allows a user to store his query as a newsfeed and automatically see when there's new content matching his query. Adding the custom links allows some clever clients to exploit the services described in the metadata.

The idea is not new, and we've had a lot of discussions on IRC, email and face to face meetings within the GeoNetwork and OSGeo communities. What I implemented in the end is a common output format in the form of an RSS feed with links that point to the W*S content type and a URL to the service. The service URL should provide enough info for clients to parse it and decide what approach to take: just continue using GetMap, or take the base URL and do a GetCapabilities request first.