I thought people on this list would want to read http://infotrope.net/2012/11/30/importing-data-is-hard/ , a list of difficulties Alex Bayley (Skud, who used to work on Freebase) experienced when attempting to reuse open data. Perhaps there are things Wikidata is already doing to eliminate some of these problems for our end users. In any case, I thought people here would be interested.