Amazon on the big EC2 outage
Amazon’s summary of the incident.
And in an email I just received:
We’ve identified that you had an attached EBS volume or a running RDS database instance in the affected Availability Zone at the time of the disruption. Regardless of whether your resources and application were impacted, we are going to provide a 10 day credit (for the period 4/18-4/27) equal to 100% of your usage of EBS Volumes, EC2 Instances and RDS database instances that were running in the affected Availability Zone.