The README contains some links to the old home of Pillow, here to be precise:
https://github.com/python-imaging/Pillow/blob/master/README.rst#what-about-image-code-bugs
besides, this information is reflected on the PyPI page of the project, though the correct new home is shown at the bottom:
http://pypi.python.org/pypi/Pillow/