I recently introduced wikidata to a (very computationally savvy) colleague by sending him this link:

His response is indicative of an interface problem that I think is actually very important: 

"Is there a simple way to get the RDF for a given concept?  The page seems to only present the english names for the concept and its linked concepts."

Leaving aside RDF, it is really not straightforward for newcomers to get from a concept page like that to the corresponding structured data.  This could be solved with the consistent addition of a simple link like "view json/xml/rdf" to each of the concept pages on wikidata.  They would just be links to the API calls: e.g. http://www.wikidata.org/w/api.php?action=wbgetentities&ids=Q423111 in this case.

As the concept pages themselves get tossed around a lot, such an addition could be extremely valuable in teaching the uninitiated what its all about and would come at very little cost - to me, this button is akin to the 'view source' action on web pages - an absolutely fundamental part of how the web grows - even now.

-Ben