If everything that was updated in the package was the addition of an entry point, this would be an irresponsible release; if any function changes in the package, you need to update the version number. How else do you know that you have the right set of features installed?
VCS, pip . pip install -e foo ; :
$ bin/pip install -e git+https://github.com/mjpieters/setuptools_subversion.git
Obtaining setuptools-subversion from git+https://github.com/mjpieters/setuptools_subversion.git
Cloning https://github.com/mjpieters/setuptools_subversion.git to /tmp/pip-e/src/setuptools-subversion
Running setup.py egg_info for package setuptools-subversion
Installing collected packages: setuptools-subversion
Running setup.py develop for setuptools-subversion
Creating /private/tmp/pip-e/lib/python2.7/site-packages/setuptools-subversion.egg-link (link to .)
Adding setuptools-subversion 3.2 to easy-install.pth file
Installed /private/tmp/pip-e/src/setuptools-subversion
Successfully installed setuptools-subversion
Cleaning up...
$ bin/pip install -e git+https://github.com/mjpieters/setuptools_subversion.git
Obtaining setuptools-subversion from git+https://github.com/mjpieters/setuptools_subversion.git
Updating /tmp/pip-e/src/setuptools-subversion clone
Running setup.py egg_info for package setuptools-subversion
Installing collected packages: setuptools-subversion
Running setup.py develop for setuptools-subversion
Creating /private/tmp/pip-e/lib/python2.7/site-packages/setuptools-subversion.egg-link (link to .)
setuptools-subversion 3.2 is already the active version in easy-install.pth
Installed /private/tmp/pip-e/src/setuptools-subversion
Successfully installed setuptools-subversion
Cleaning up...
; "", pip "" VCS, setup.py egg_info.
; VCS . , , .