PyPy is coming along nicely. It gets closer to matching CPython for speed every day, but it still has its problems. It brings more questions to my mind about the matter of duplicated efforts with all of these Python implementations.
What we really need is a standardized from of representing Python code in Python code. Things like a Statement class and Expression instances, for example. This would allow people to easily write code to optimize and analyze code parsed by any front-end and compiled to any back-end.