The SSL certificate expired shortly after 16:00 EST which prevented all its customers from accessing the service. Microsoft revealed that the HTTP services were not affected. On its website, Microsoft noted, "Beginning Friday, February 22 at 12:44 PM PST, Storage experienced a worldwide outage impacting HTTPS operations (SSL traffic) due to an expired certificate."
The company also noted that its Xbox Music and Video Store were also affected but, there was no direct connection between these and the Azure outage. But, it seems that because of the storage outage, other services were also affected. The Azure outage lasted for a full 12 hours. "We apologize for any inconvenience this causes our customers", noted Microsoft.
Just a few hours back though the Azure service was restored after it acted upon the expired certificate. In a post on Windows Azure Services Dashboard Microsoft noted, "We will continue monitoring the health of the Storage service and SSL traffic for the next 24 hours."