Matt's latest blog entry shows how to use unittest2 to run IronPython unit tests in the forthcoming SharpDevelop 4 IDE:
SharpDevelop 4 has been updated to support running IronPython unit tests that use the unittest2 library.
Make sure unittest2 is on the Python path before running the unit tests.
Out of the box SharpDevelop will actually use the unittest library's test runner. This seems to work however if you actually need to use the unittest2 test runner then you can modify the following two files in the folder: AddIns\AddIns\BackendBindings\PythonBinding\TestRunner.