
While it's dead easy to customize the delicious sidebar plugin (it's just a matter of search for delicious and replace it with magnolia ... it really works), I doubt it is the right way to create an individual plugin for each and every service out there.
So, how about extending the existing delicious plugin? Should be quite easy to add other services from which you can pull your bookmarks via RSS. We'd need another option for service name and/or service URL.
OTOH, it could make adding new features to the plugin a bit more complex, if services or service APIs differ too much.
Opinions? Anyone interested in this at all?