"2to3c: an implementation of Python's 2to3 for C code"
See http://dmalcolm.livejournal.com/3935.html for a description of this tool.
It works on C modules. So it should be easier for people to do ports to py3k for their C modules.
The 2to3c tool uses Coccinelle for transformations on the C code. This program has been used for linux, and other software... for updating code when their APIs change.
The perfect fit for the python C API changes!