FYI: ROS Docker images from the Official Library registry have also been updated to reflect the above key rotation. Please be sure to sure to pull the latest images before rebuilding any dependent tags.
As @gerkey mentioned in the original thread, a big thanks to @tfoote, @nuclearsandwich, and @jrivero for the many hours and late nights they put into getting us back on track. Cheers! 
P.S. for tracking when update images get finally synced to the docker hub registry: