I've just released a new Python 9P client implementation. It's based largely on my r9p library, but is a good bit cleaner and faster. It has a simple but high level client library and should be fully thread safe. The serialization code is based on a high level message specification, so adding new data types is as straight forward as reading a spec and translating it into Python. I suspect that that will be useful to at least some people who want to implement high level IPC on top of 9P.
For the moment, it's bundled with wmii, but I'll release it separately after it's been thoroughly broken in:
I believe that when I die I shall rot, and nothing of my ego will survive. I am not young, and I love life. But I should scorn to shiver with terror at the thought of annihilation. Happiness is none the less true happiness because it must come to an end, nor do thought and love lose their value because they are not everlasting. --Bertrand Russell