I have built a kernel based on kernel-2.6.29-0.41.rc2.fc11.src.rpm and Changeset 2342 from http://xenbits.xen.org/paravirt_ops/patches.hg/ and uploaded selected files which are at http://compsoc.dur.ac.uk/~may/xen/kernel-2.6.29-0.41.rc2.pvops2342.fc10.src.... http://compsoc.dur.ac.uk/~may/xen/kernel-2.6.29-0.41.rc2.pvops2342.fc10.x86_... http://compsoc.dur.ac.uk/~may/xen/kernel-firmware-2.6.29-0.41.rc2.pvops2342....
I got it to boot as Dom0 with a Rawhide based live CD image on a USB stick with several kernel tracebacks. I have not managed to get it to boot on my main Fedora 10 system either dom0 or as an ordinary kernel (but nor does the the unaltered kernel - presumably there is some incompatibility between Fedora 10 systems and Fedora 11 kernels that I haven't spotted yet), so you use it very much at your own risk.
Michael Young