By default, in the yum config, kernel* is listed in the exclude list to ensure
that a kernel is not accidently installed during a system update.
Yum however does not document a method to override this excludes setting, and
use yum to install upgraded system kernels.
Either the documentation is missing, or this functionality is missing and is
therefore a regression from up2date.
The admin is forced to use the error prone and time consuming option of
downloading rpms and installing them manually.
The functionality was not there in 3.0.1, the functionality and documentation
should be there in the current RHEL-5.2 beta version (3.2.8).