ported to python-2.6 & is a bit more stable (written a few py3k programs
w/ it).  the patches have been simplified & consolidated to a single
file: ceval.c

u can also test out scripts generated by 2to3 by adding to them the
magic line:
"from __future__ import py3k_syntax"

an example "python-2.6" script using "python-3.0" language syntax (&
numpy if its installed) is provided @:
http://www-rcf.usc.edu/~kaizhu/work/py3to2/current/example_py3k.py

new features added by patch to python-2.6 (under py3k_syntax mode):
  pep3102  Keyword-Only Arguments
  pep3104  Access to Names in Outer Scopes
  pep3107  Function Annotations
  pep3111  Simple input built-in in Python 3000
  pep3113  Removal of Tuple Parameter Unpacking
  pep3114  Renaming iterator.next() to iterator.__next__()
  pep3115  Metaclasses in Python 3000
  pep3127  Integer Literal Support and Syntax
           - oct() functions differently in py3k_syntax mode
  pep3129  Class Decorators
  pep3132  Extended Iterable Unpacking
  pep3135  New Super
  misc     exec becomes a function

sans unicode & py3k's builtins module, the above (plus __future__)
implements pretty much all of py3k's language syntax

py3k_syntax mode:
  a special bitflag is embedded in codeobj->co_argcount, which triggers
PyEval_EvalFrameEx to enable the backported opcodes (which r disabled by
default) & use an alternate py3k __builtin__.

  codeobj->co_argcount now limited to range 0-0xffff with upper bits
reserved for py3k flags

  codeobj->co_kwonlyargcount (limited to range 0-0xff) is embedded in
upper bits of codeobj->co_argcount

most of the trouble have been gettin kwonlyarg, annotations, & classes
to work.

there is one unrelated opcode (LOAD_ATTR_py3k) added to ceval.c for my
personal use (curries attributes as a universal function), but can b
safely disabled by commenting its case out of PyEvalFrameEx in ceval.c &
deleting it from dict opnew_py2x in py3to2.py