Ron Daniel has posted an updated version of the XML Linking Working Group's XLink to RDF mapping.
Originally set to be an appendix to XLink itself, it has now been decided that the mapping will be submitted as a W3C Note.
In the mapping, each XLink arc gives rise to one RDF statement (a triple), where the start and end resources map to the RDF subject and the object, and the arcrole to the predicate. However, as the spec observes, there are some "corner cases", which are given fuller treatment in the document.
As linking and indexing technologies such as topic maps gain ground, their relationship to XLink and RDF will be interesting to watch--and, indeed, whether the architects of XLinking or topic map systems consider RDF necessary for their purposes.