We should have a small helper script which we defer to for doing installations in a virtual env. The script can try easy_install first if it's installed (binary support on Windows), pip next, etc... It can also have different behavior on Python 3.3 where we need to do venv support and pip isn't there. Finally, it can return stable error codes indicating what went wrong, so we can help the user install easy_install or pip if they don't already have it.