Have decided to go with Fedora 13 for my Xen install. Reaons being:
VMWare and XenServer don’t support USB Passthrough, which I want to run one of the VMs as a home server, and will pass 2 printers through to it.
CentOS is running off an old kernel and Xen version. If I want the latest and greatest, I’ll have to hack something together, so might as well use Fedora.