There is a 2.6.37 kernel to test (2.6.37-1.xendom0.fc15) at
http://koji.fedoraproject.org/koji/taskinfo?taskID=2703408
I have had mixed success with this as the kernel package doesn't boot, but
the kernel-debug package does boot to runlevel 3 (albeit with the couple
of minutes delay which I have been seeing in the 2.6.37-rc kernels).
Michael Young