Hi
Actually, I don't understand why people find the Fedora kernels so attractive. They are rarely any improvement on the standard kernels from http://www.kernel.org .
Well thats a deliberate design decision. Fedora packages as far as possible does not deviate from upstream ones. So when you come across a bug you can almost be sure that its a upstream one. Further every additional patch results in added work, so its important that developers evaluate the cost vs advantage of having it. However the kernel does have a few improvements like exec shield including several bug fixes parts of which has already been merged upstream.
regards Rahul