The Ironclad project[1] claims to have created a formally-verified differential privacy database. I recommend watching the demo video, the development efficiency they saw using formal verification is jaw-dropping.
Google recently put a tool called RAPPOR into production that's partially based on differentially private randomized response for collecting usage statistics about Chrome users.
I certainly hope Betteridge's law of headlines does not apply here. Differential privacy is an amazing criterion, and I'd love to hear about anyone who has put it into practice on data they're releasing.
[1] https://www.usenix.org/conference/osdi14/technical-sessions/...