Hmm. I've never used SciPy before but let's see if I can figure it out:

$ brew install python pip gfortran # Fortran's for scipy...

$ pip install numpy

$ pip install svn+http://svn.scipy.org/svn/scipy/trunk/#egg=scipy

If you don't want to use the SVN version of SciPy, you can just use:

$ pip install scipy

Homebrew and pip are the first things I've ever used that made me not miss apt on debian.