OpenStack is similar( to the Linux kernel, in (that vendors add value( around it to make it( practical to deploy and (maintain. A number of companies, including( big players like HP and (startups like Nebula and (Piston Cloud, are doing just that. Others, including Red Hat and Rackspace, are offering their own fairly raw OpenStack distros wrapped in scripts to ease deployment. In other words, for the most part, the fully packaged OpenStack solutions are still being baked, and only the boldest customer would consider downloading, installing, and firing up OpenStack for anything except experimental purposes -- especially when the bits are undergoing major revisions every few months.
Meanwhile, OpenStack is hardly the only game in town. VMware probably has one of the more mature commercial private cloud solutions, thanks mainly to vCloud Suite. Plus, one of the big cloud events of 2012 was VMware's $1.2 billion acquisition of Nicira, a hot little network virtualization company that, along with Cisco, has led the development of the Quantum network service component of OpenStack. Then there's Microsoft -- Windows Server 2012 and System Center 2012, released this year, together offer a viable private cloud solution.
Two other open source players deserve mention. Eucalyptus is a private cloud stack intended to mimic Amazon Web Services, with full API compatibility. CloudStack, an open source project launched by Citrix in April 2012, is well-positioned for use by cloud service providers, featuring a great Web UI for administering cloud resources.