Don't check PyPI for new versions of pip by default, updates will occur when
new releases are added to the tree.

--- pip-6.0.2/pip/cmdoptions.py
+++ pip-6.0.2/pip/cmdoptions.py
@@ -404,7 +404,7 @@
     "--disable-pip-version-check",
     dest="disable_pip_version_check",
     action="store_true",
-    default=False,
+    default=True,
     help="Don't periodically check PyPI to determine whether a new version "
          "of pip is available for download.")