Ok, so after realizing I was using the I586/i686 DVD to install onto my new Core 2 Duo, I re-downloaded the X86_64 DVD.
Once installed, grub only shows the 2.6.18-1.2798.fc6xen kernel to be listed, but there is only a Xen kernel, no other one.
I've searched and found that Xen is a virtual system manager or something along those lines, but sounds like I don't really need it.
I've been using yum/yumex and I have selected to remove 2.6.18-1.2798.fc6xen and install kernel.x86_64 0:2.6.20-1.2933.fc6.
What else must I do to get rid of xen, and the xen kernel? Thanks!