Apple has updated its iCloud System Status page with a much more comprehensive page breaking down outages by service and showing recent outages in a detailed timeline. The old system simple offered written status updates in a more free-form fashion.
Over the past year, Apple has seen various iCloud services go offline several times. Just today, some users were unable to access iCloud mail, iCloud Documents, Photo Stream, and Backup & Restore.
Article Link: Apple Expands iCloud System Status Page After Repeated Outages