Kilo has been released last week.
This blog post is the first of a series that will demonstrate some nifty new features.
Managing cloud images life cycle is a real pain for public cloud providers.
Since users have the ability to import their own images they can potentially introduce vulnerabilities with them.
Thus the cloud operators should be able to deactivate (temporary) an image to inspect it.
Later operators can reactivate it or just remove it if they believe the image is a threat for the cloud environment.
Another use case, as well is for cloud image updates, while performing the update of an image the operator might want to hide it from all the users.
Then when the update is complete he can reactivate the image so the users can boot virtual machines from it.