I think wikidata is and will be a mayor player as the database of everything. It is still in its early development but it already has a lot of data and huge potential for additional informations. It is already used a lot. The Peerage is just one of the sources. I am preparing to make WikiTree an actual source for wikidata. I will add a wikitree reference for matching data and I will probably populate the missing or different data based on WikiTree.