I am introducing the check command in Distutils. This command will check your package metadata, like the sdist and the register command already do (they display warnings).

But the new thing is that it will also allow you to check if long_description is reStructuredText compliant.

Its usage will be:
$ python setup.py check --restructuredtext

running check

warning: check: Title underline too short. (line 32)

warning: check: Title underline too short. (line 32)

warning: check: Could finish the parsing. (line None)

And there's also a strict mode, that raises an error in case something is wrong
$ python setup.py check --restructuredtext --strict

running check

warning: check: Title underline too short. (line 32)

warning: check: Title underline too short. (line 32)

warning: check: Could finish the parsing. (line None)

error: Please correct your package.

Last, this command will be used by register, and sdist, so you can stop the process in case the metadata are not correct. This is useful to make sure your PyPI home page is not broken for example, since it parses long_description to build it. So a good practice will be to use strict when registering a package:
$ python setup.py register --strict

running register

running check

warning: check: Title underline too short. (line 32)

warning: check: Title underline too short. (line 32)

warning: check: Could finish the parsing. (line None)

error: Please correct your package.

This feature will land in Python 2.7 (I am working on it and it should be commited this week end). Of course, it will not introduce a hard dependency on docutils in Python, neither it will change the current default behavior.

Until then, you can use collective.dist 0.2.3, that provides this feature for Python 2.4 to 2.6