FWIW, at some point I will need to do some serious work on this code for Python 3.5, so I'll certainly take your suggestions into account there. But I won't be doing the same for old versions of Python - at most 2.7 may get a check for the extra registry key, but 2.6 and 3.0-3.2 will still need to be using setuptools>=6.0 (which 2.7.10 will ship with).

Also, pip forces setuptools onto packages whether they like it or not, so pip installs should always build. Because it's a monkeypatch, "import setuptools" is sufficient to port old setup.py files.

All together, there doesn't seem to be an urgent need to get this into the core release. If someone comes up with a simple patch I'll happily review and apply it (and Jason will want a setuptools patch to skip the monkeypatch there), but I need to spend my own dev time on the next release.