RDO will serve as a new open-source community-based OpenStack distribution for Fedora and Red Hat Enterprise Linux (along with other "EL" derivatives). Effectively, Red Hat RDO is a new proving grounds for Red Hat prior to introducing new OpenStack functionality within their commercial products. In the OpenStack world, RDO is to Red Hat OpenStack as is Fedora to Red Hat Enterprise Linux.
Red Hat's press release says, "It offers a pure upstream OpenStack experience with the latest stable release from OpenStack.org, packaged, integrated and easy to deploy on Red Hat platforms. The community at openstack.redhat.com offers the opportunity to interact with other users of OpenStack on Red Hat platforms, to share knowledge and build capacity. RDO brings the core OpenStack components – Nova, Glance, Keystone, Cinder, Quantum, Swift and Horizon – as well as incubating projects Heat, for cloud application orchestration, and Ceilometer, for resource monitoring and metering. Installation is made easy with the Red Hat-developed installation tool, PackStack."
Meanwhile, Red Hat announced at the same time that its Red Hat OpenStack for customers has moved on from being in a preview version to now being in an "early adopter" program.