Google just announced the forthcoming end of their personally controlled health care record Google Health due to lack of widespread adoption. We have been working with the service since its launch in 2008 and used it as a back-end for various projects (most recently for a medication reconciliation tool tied to the SMART platform). Google Health was offering a very decent user interface, a fair amount of API support and some really good interfacing ideas; I hate to see this one go.

[UPDATE] You might deduct how important the project was in the end from the fact that it was not even worth a shutdown announcement for itself.