FYI, in both Fedora 7 & and Fedora 8, I have got new updates of the Xen userspace to be sync to the latest Xen 3.1.2 bugfix release available for testing. If you wish to test this, you can do
yum --enablerepo=updates-testing update xen
If there are no major problems reported I will push these to 'updates' in about a week.
Regards, Dan.