I've put my Openstack XenServer 6.1 (Tampa) installer onto Github here: https://github.com/amesserl/xs-tampa-openstack.
It has all of the modifications to get it running with the XenAPI Openstack Nova code and also includes the latest hotfixes. All you need to do is snag the latest CD and drop it in. I'll continue to publish repos for new versions as they come out (Clearwater should be released soon). You can also boot it from osimag.es as well.