Looks like Xen 4.1 went through some major changes as far as networking goes. With that said, I have two NICs on the host. eth0 and eth1. I want dom0 to be accessible via eth0 and only eth0. I want eth1 for ALL virtual machine traffic.
I went through the configuration and setup the bridge via /etc/sysconfig/network-scripts/ifcfg- per the wiki.
I have it working where I'm able to log into the dom0 and created a VM. However, my VM doesn't go over eth1. Looks like it attached itself to the default bridge that was automatically created during initial setup (virbr0).