This is a minor new release of South.
None.
South’s internal test suite now doesn’t run by default (the SKIP_SOUTH_TESTS setting now defaults to True). This is mainly because the test suite is meant to be run in isolation (the test framework continually changes INSTALLED_APPS and fiddles with the ORM as it runs, among other things), and was causing compatability problems with other applications.
If you wish to run the tests still, simply set SKIP_SOUTH_TESTS = False.