Currently Wikidata hosts more thenthan 43M statements<ref name="wikidata-stats">[https://tools.wmflabs.org/wikidata-todo/stats.php Wikidata stats] on WMFlabs by Magnus</ref>. On the other hand OpenStreetMap has 2.7 billion objects (''nodes'', ''ways'' and ''relations'') in it<ref name="osm-stats">2.5 billion of which are points, see [http://www.openstreetmap.org/stats/data_stats.html OSM data stats]</ref>. Every object is OpenStreetMap has some [http://wiki.openstreetmap.org/wiki/Map_Features features] which are expressed using key-value pairs, for example to say that [http://www.openstreetmap.org/relation/1834818http://www.openstreetmap.org/relation/1834818 this relation] is named "Colosseum" you have to add to it the following data: <code>''name''=''Colosseo''</code>. Analogously Wikidata uses [[:wikidata:Wikidata:Glossary#Entities.2C_items.2C_properties_and_queries|properties and values]] to enrich its items.
The idea is to use a MediaWiki + Wikibase install to build a tag editor for OpenStreetMap.
