Shawn Farkas just let me know that the latest Iron Python 9.3 release breaks my Iron-Python Mdbg sample:

So the 0.9.3 release breaks the mdbg extension – the fix is pretty quick though. When creating the streams to redirect stdin, out, and err through you now have to supply a stream name. The sys object also moved into the IronPython.Objects.Ops namespace. Replacing the current redirection with:
        IronPython.Objects.Ops.sys.stdin = new IronPython.Objects.PythonFile(s, "stdin", "r", false);
        IronPython.Objects.Ops.sys.stderr = new IronPython.Objects.PythonFile(s, "stderr", "w", false);
        IronPython.Objects.Ops.sys.stdout = new IronPython.Objects.PythonFile(s, "stdout", "w", false);

Should get it off the ground again.

I've updated the sample code snippet here, and will go back and update my "how-to" steps.

Update: I've downloaded IP9.3 and verified this works.
[Update 1/24/06] Updated again for Iron Python Beta 1