With this release, AMIs are available for 32 and 64-bit PVM (paravirtualized) and 64-bit HVM (hardware-assisted virtualization). The new HVM support means that you can now run RHEL on a wider variety of EC2 instance types including the Cluster Compute (cc), High Memory Cluster Compute (cr), Cluster GPU (cg), High Storage (hs), and High I/O (hi) families (availability of instance types varies by Region).
RHEL 6.4 now includes support for the popular CloudInit package. You can use CloudInit to customize your instances at boot time by using EC2's user data feature to pass an include file, a script, an Upstart job, a bootstrap hook to the instance. This mechanism can be used to create and modify files, install and configure packages, generate SSH keys, set the host name, and so forth.
This release also changes the default user login from "root" to "ec2-user".
More information on the availability of Red Hat Enterprise Linux, including a global list of AMI IDs for all versions of RHEL can be found on the Red Hat Partner Page.Support for these AMIs is available through AWS Premium Support and Red Hat Global Support.