I've learned a lot working in the clouds. One of the most important things I've learned is the need for backups. And not just one backup. Lots of them.
You need to backup operating systems and configurations using Amazon bundling to AMI.
Also in addition to backing up everything to Amazon S3 every night I have adopted a plan B as well. I am now backing up to the Rackspace cloud as well.
This provides me with not only the latest backup and previous versions, it gives me another completely redundant layer to all my backups.
Peace of mind...