Recently I have been playing around with oVirt.
Since oVirt is included in Fedora 18, I tried it on F18 first. Unfortunately, these packages lack the web GUI. Since this is one of the things I wanted to test, these packages are useless to me. So I started digging around, and found the ovirt-dre repository.
You can use the above repository on EL6 to install both oVirt Engine, the management application, and VDSM, needed by oVirt Engine to manage a virtualization node. I am not getting into detail on how to install and configure oVirt, as there are already enough guides out there. I just wanted to point out the existance of this oVirt for EL6 repository.
For the oVirt Engine to be able to use your CentOS 6 virtualization host, you'll need a few packages that are in third party repositories. Obviously you need to install the vdsm-dre repository for the VDSM packages, but you'll also need EPEL for mom and maybe a few other packages. I also needed several GlusterFS packages, though they might be optional, as I enabled GlusterFS in oVirt engine. For GlusteFS, you might need the 3.4.0 pre-release packages, because some XML output has changed, causing earlier packages not to work with recent oVirt engine. Should you require these newer GlusterFS packages, there is a staging repo with 3.4.0 pre-release packages.