It would be fantastic if we could query CDS via OData, REST or similar from outside.
This would mean we could extend CDS usage to SharePoint, perhaps to Nintex Workflows, to Salesforce as external objects, to our apps. It could really become the central part of a lot of our applications once refreshing the data is worked out.
I would definitely pay for this ability as a premium service, to be able to use Data Factory to upload my corporate datasets to Azure Data Lake or similar, query them using Power Query, and have a centralised data service for all my apps.
If it had security similar to Azure Storage Tables, so I could craft a URL to query, it'd be fantastic.