Update 8/1: The fix I described below has just been added to the development branch. Mountain Lion users can install the development branch with:
pip install -e git+https://github.com/scipy/scipy#egg=scipy-dev
(note this requires a Fortran compiler; see here for more detail)
Trying to compile the stable version of SciPy under Mountain Lion results in errors. It can be fixed by adjusting four files that refer to the deprecated vecLib library and need to be updated withApple's Accelerate framework. A pull request containing the fix has been submitted but not yet accepted into the development branch, and even upon acceptance may take some time to appear in the stable version. In the meantime, cutting-edge users will need to install SciPy from the modified branch. The following code will do the trick -- at your own risk!!
pip install git+https://github.com/minrk/scipy-1.git@accelerate
Please note that this fix is not guaranteed to be bug-free -- in fact, it will fail some BLAS tests. If you absolutely need a stable version of SciPy, you should consider holding off on upgrading to OSX 10.8 until it is fully supported by the main SciPy branch.