It has more informative default output useful for testing things that take out the interpreter halfway through the test script (like segfaulting C extensions).  Instead of printing dots as tests are run, it prints the testname.  It also has other features, listed below.

Changes from 1.2.0 to 1.3.0
---------------------------

* Clearer and more verbose text output format
* Tests run in text mode can now be interrupted using ctrl-c
* New FunctionTestCase class provides support for wrapping legacy test
  functions into PyUnit test case instances
* Code is now compatible with JPython (new example: examples/withjpython.py)
* Support for short descriptions of tests, taken from __doc__ strings
  by default
* Updated and expanded documentation
* Tested with Python 2
* Changed module reloading mechanism in GUI test runner to fix a problem
  with Python 2 on Win32 reported by Henrik Weber (bug 125463)
* Convenient new unittest.main() function for use by all test modules

For more information, see http://pyunit.sourceforge.net