A wikidata project could use semantic mediawiki from the outset, and be seeded with data from dbpedia.
A lot of existing & proposed projects would benefit from a centralised wikidata project. e.g. a genealogy wiki could use the relationships stored on the wikidata project. wikisource and commons could use the central data wiki for their Author and Creator details.
+1
Could this be part of dbpedia?
SJ