Chris Anderson is jumping on the Python bandwagon and is building support into AvPad for IronPython as a scripting language. Pretty interesting stuff. In his latest post, he has extended IronPython to support ICustomTypeDescriptor so that you can interrogate an IronPython object at runtime and discover properties that may have been added on the fly. The main purpose Chris added this is beause it is actually one of the interfaces Avalon will use for reflection as he shows here in a databinding example.
On a related note, I wonder if IronPython already has support for IExpando? If not perhaps they should consider adding it for even better interop since, when communicating with COM, classes implementing IExpando will be exposed as IDispatchEx making them richer in environments that support the interface (i.e. scripting languages).