- - Distribute / setuptools merge, e.g. cratering folks who use a
distro-managed 'python-distribute' package.

This is the biggest issue. I wasn't involved and it could have been handled better sure.

what issue are we talking about exactly?

I'm aware of the "Import setuptools" problem during upgrades from distribute to setuptools: https://github.com/pypa/pip/issues/1064

pip-1.4 does prevent that now (released last week)

but you specifically mentioned the linux distro name, "python-distribute"?
I'm guessing maybe you're concerned with the scenario of how upgrading some project (that depends on setuptools/distribute) forces an unintended upgrade of distribute on a system where distribute is system-managed.

Is there a link to a tracker issue for that somewhere?

but on 2nd thought, this is not a new problem. this would always been happening, just not involving a transition to setuptools.

so I imagine, your concern was just the "Import" error?