[Libvir] <model>e1000</model> - Specifying model in XML Configs

Hi guys, I just tried to port a few customers over to this libvirt setup i'm hoping to run and I couldn't get their machines started because there's no mechanism to specify a model in the XML! I know redhat have changed KVM's default driver to e1000, which I think is the one I like the most and almost if not all of my VMs use. Ubuntu haven't done that yet however! Is there a model directive in the latest version? In the works? Just so I know which solution I should pursue (updating libvirt or harassing ubuntu to change the default) Thanks, Henri