About your first point, the RDF format, I want to mention that it is still in development. It allows networking of data sets between various portals. It requires a lot of work. Within our open data initiative in Canada, we work with provinces and municipalities to allow for a joint search across many portals. We plan to use the RDF format, although not right away, but at some point.
On May 5th, 2014. See this statement in context.