This presentation is not only interesting for Drupal developers; it's a great starting point for learning about what cloud computing is, the difference between platform-as-service and infrastructure-as-service, a list of companies offering these services, what some dangers and benefits are... and more. They detail what it takes to put Drupal into the Amazon EC2 service, and show a video of what a Firefox-based cloud administration tool looks like.
More Drupalcon videos here
P.S.: The sound isn't perfect, though =)