From the Wikidata Mailing List (via Wikimedia Tech News):
The Discovery Department at the Wikimedia Foundation is pleased to announce the release of the Wikidata Query Service.
You can find the interface for the service at https://query.wikidata.org.
The Wikidata Query Service is designed to let users run queries on the data contained in Wikidata. The service uses SPARQL as the query language.
You can see some example queries in the user manual.