I think it would be cool to use http://mappings.dbpedia.org/ - it already has
mappings for hundreds of templates in different language versions to the dbpedia
vocabulary. If we added a mapping for wikidata <-> dbpedia, it should be easy
enough to derive a mapping between a wikipedia template and wikidata. Actually,
I was under the impression the wikidata <-> dbpedia already existed, but I don't
see it on the site right now. Adding Anja Jentzsch, she might know.

Even if it proves too tricky to map individual template parameters this way, it
should still be possible to at least detect the class (instanceof) of an item
based on the templates the respective wikipedia page contains. We should
definitely map dpedia classes to wikidata items.