I have subscriptions to Red Hat Enterprise Linux already, can I use these on-preemise or at EC2?
No. While the technology and support are in most cases identical to what is provided via comparable on-premise subscriptions from Red Hat, there are significant differences in how images (AMI’s) are managed and metered. During the beta period, Red Hat will not permit the re-use of on-premise subscriptions within the EC2 web service.