Very interesting! Jörn, I'd agree more with your advice in JIRA comments about making it more generic - Entity rather than just Geo. Afterall, we have 4 fundamental entity types (person, location, organization, event) and all but the last have various relatively simple to use gazetteers. One can event think about Wikipedia as generic gazetteer.
I didn't get exactly why one would need PostGIS for this compared to just a database, but that implementation issue. It's more important to have the interface designed properly.
