Some more explanation for why keeping distutils Python 2.3 compatible is
desirable:

distutils was removed from the PEP without any public discussion outside
a sprint at PyCon and the reasons given for it did not take into account
that people will want to use a single distutils version (that of the
lastest released Python version) to build packages for multiple Python
versions.

distutils in Python 2.6 no longer works with Python 2.1, but it still
does mostly with Python 2.3 and I would prefer to have to use that
version as minimum required.

Over the years I've always tried to rework any changes that were done
which did not meet that requirement and only left non-Python 2.3 code
in place that was not relevant for that version anyway, e.g. the
new MSVC code for Python 2.6.

Please also note that distutils is not a performance critical piece of
software. Making it more developer friendly to extending via
sub-classing and more user friendly by adding more support for platform
specific installer format is much more important than using the latest
and greatest tricks in Python.

With Python 2.7 released, we can then move on to Python 2.4
compatibility and so on.