Xen virtualization is still strong, fedora just isn't porting the kernel patches upstream anymore. I believe Novell has a 2.6.27 kernel with xen patches. I would think it to be possible to pull down the kernel source from Fedora, build the config, then pull in suse kernel source, run make oldconfig, and compile your own kernel for fedora using the suse sources. I've never tried it and fully understand that this is an unacceptable option for most fedora users.
I've been following the fedora-xen mailing list and they would still like to put xen back in, but not until it's in the upstream kernel. As stated at the F9 release, they feel it is counterproductive to maintain 2 different kernels, which I can't disagree with them on. The latest news I heard is that they were hoping the 3.4 release of xen to have pv_ops dom0 in the kernel. Wether or not that it's Linus' kernel, they haven't really stated. If fedora is waiting for pv_ops dom0 to make it into Linus' kernel, then I would have to agree that xen will slowly dissapear and KVM will be the way to go. I see that as an uphill battle for the xen team since kvm is already in the kernel.
http://fedoraproject.org/wiki/Docs/Beats/Virtualization for more information on f10 virtualization.
