Patch looks good to me. I've added 3.3 to the list of python versions because it might be worthwhile to apply this to 3.3 as well (after 3.3.0 is released).
This is an alternate patch, it replaces the PyObject_INIT and PyObject_INIT_VAR macros by inline functions with macro wrappers for compatibility (the macros are used to suppress type warnings). I don't particularly like my patch, but it might be a better way to ensure that the warning stays away and also fixes the warning in 3th-party code. BTW. I wouldn't mind feedback of other core developers on either patch.