[fedora-virt] xen 4.2 and libvirt

I would like to update the xen version on rawhide and probably also Fedora 18 to xen 4.2.0 , however libvirt links against some xen libraries whose versions have changed in xen 4.2 and when I looked a few months ago it seemed that libvirt didn't support the newer library versions. Does anyone know what the current support status of libvirt for xen 4.2 is, and what work might be going on (if necessary) to add it? Michael Young