App Engine 1.7.3 was just announced, claiming "Django 1.4 is now fully supported for Python 2.7". Please provide more information. Is this referring to the django-nonrel source code on Github for 1.4 ?
No, not django-nonrel. This announcement means that you can now use Django 1.4 as part of your libraries directives in app.yaml as documented here: https://developers.google.com/appengine/docs/python/tools/libraries27