The Red Hat 6 Beta is out, and there is no Xen in it, only KVM. It can operate as a guest in an existing Xen environment, but it cannot act as a Xen host. A few minority interests still cling to Xen, but ultimately it makes no sense for most Linux distributions to ship with Xen. Novell will stick with Xen for a while, and also Oracle, because they are no friend of Red Hat, but when the hypervisor wars become old news, they will quietly move to KVM. It’s easier. In future we fully expect to be talking about Xen/Linux in the past tense.