Azure users now have the option to send a single backup to multiple storage accounts. The use of multiple storage accounts provides additional flexibility and higher throughput.
To use multiple storage accounts, you can add storage accounts to the target group by using the BAR Setup portlet or the command line.
If you use the command line there is a new XML format. You can use export_config to get the new format and edit the XML. See also config_target_groups and config_target_group_map.
If you want to continue to use a single storage account, you aren't required to change anything.