RAC uses shared disks (http://www.oracle.com/technetwork/database/clustering/overview/twp-rac11gr2-134105.pdf http://www.oracle.com/technetwork/database/cluster

RAC uses shared disks (http://www.oracle.com/technetwork/database/clustering/overview/twp-rac11gr2-134105.pdf http://www.oracle.com/technetwork/database/clustering/overvi...) So unless EBS or an EBS-like service will allow the attachment of a volume to multiple instances or Oracle changes how RAC works, there won't be Oracle RAC on AWS.