Karan (see the Blogs I read section for his weblog) pointed me to this and I think it is pretty cool. IronPython is a new implementation of the Python language targeting the CLR. It compiles python programs into IL that can run on either .NET or Mono (now that is cool). This produces a standard assembly that other code can reference. It would be an interesting exercises to see the IL it produces and see if we can infer anything from that.
IronPython can run fast on .NET. Python is an extremely dynamic language and this offers compelling evidence that other dynamic languages should be able to run well on this platform. However, implementing a dynamic language for the CLR is not a simple process. The CLR is primarily designed to support statically typed object orienter and procedural languages. Allowing a dynamic language to run well on this platform requires careful performance tuning and judicious use of the underlying CLR constructs. You can read more on the perf. results of this here.