I tried to port the extension module at http://code.google.com/p/pyhyphen/source/browse/3.x/hnjmodule.c to the stable C API using abitype.py. I gave up after the following exceptions:
- execption raised for missing PyVarObject_HEAD: this could be rixed by deleting a /* */ comment before. I think abitype.py should properly skip comments rather than forcing the user to delete them.
- the xxxmodule.c on which hnjmodule.c is based, defines a PyObject Str_type wherr tp_basicsize is 0 rather than sizeof(XXX). This causes abitype.py to raise a key error as '0' seems to be ignored by abitype.py.

Finally, I suggest to add to the source tree a boiler plate C module conforming to the stable API such as xxxmodule-stable-api.c. This would help creating extensions from scratch.