While the database copy function is useful in some scenarios, we really need a full, VERSIONED backup solution for SQL Azure.
We have scenarios all the time where users make mistakes and ask us to check the backup from up to 2 months in the past. We currently run daily backups which we retain for 60 days which allows us to do this.
The only way we would achieve the same thing in Azure would be to copy the database to a new db every day and drop the database from 60 days ago. That means we would be paying MS for up to 61 databases!!
The sticking point here is that you guys already have the technology - Data Protection Manager - to make fast block-level incremental backups! Work with the DPM team to either implement this service in the cloud, or at the very least enable it for our on-premises DPM servers. This would be the ideal solution for us.
Implement it and watch you sales go through the roof...