По крайней мере, это сработало для меня:
$ brew install pypy
$ pypy -m easy_install ipython
$ /usr/local/share/pypy/ipython
Python 2.7.3 (480845e6b1dd, Jul 31 2013, 10:58:28)
Type "copyright", "credits" or "license" for more information.
IPython 1.1.0 -- An enhanced Interactive Python.
? -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help -> Python's own help system.
object? -> Details about 'object', use 'object??' for extra details.