A lot of people use URLs like http://www.wikidata.org/wiki/Q42 as URI of Wikidata entities instead of http://www.wikidata.org/entity/Q42 because they are used to Wikipedia articles URLs.
It would be nice to have a more prominent display of the entity URI (maybe close to the entity ID that is currently displayed near the label) than the small "Concept URI" displayed in the sidebar in order to decrease this phenomenon.