IronPython is good if you want to bring in Python into a .NET world. Python for .NET is good if you want to bring in .NET into a Python world.
As for your learning concerns, there need be none. There is really nothing to learn extra for the integration. They just work. Once you learn the .NET framework and Python, there isn't much to know additionally. While you are on topic, check out Boo. It is not the same as the ones you mentioned but you might find it interesting and useful while working with .NET if you have Python tastes. -- http://mail.python.org/mailman/listinfo/python-list
