Create an Azure Master Data Services service
Master Data Services, as part of Sql Server, with its excel interface is a brilliant tool for maintenance of reference data, hierarchies and manual maintained groupings for analytics and data warehouse purposes.
It would make a very good Azure service. It would give Microsoft the opportunity to rebuild the administrative interface to a modern, Azure like interface.
The Excel interface is the brilliance of it, and to call an Azure MDS service a very simple thing to maintain.