Yes. This was a fresh install of 6.3 minimal 64-bit. The only difference I could see in the walkthrough was my libvirt was slightly newer:
libvirt-client-0.9.10-21.el6_3.4.x86_64 (this is from memory, I can reconfirm once I get back in front of the box)
Would that make a difference?
Follow up - just confirmed the libvirt version:
# rpm -qa | grep libvirt
And double-checked that selinux was disabled.