With the test discovery changes in 1.6, the tests for django.contrib apps are no longer run as part of a user's project. For this reason I believe we no longer need to decorate tests in contrib.auth, formtools, and flatpages with @skipIfCustomUser. Is that correct? If so, should we keep the decorator at all? It is documented, but it's not clear to me if the test runner changes were meant to discourage writing these sort of "integration" tests or not.
@skipIfCustomUser may not have a use in Django's own test suite, but I can see it being useful for a while for projects that are migrating (slowly) away from the old test runner.